Mike Santorelli and Cory Stillman netted shootout goals and goalie Scott Clemmensen denied Seguin, the No. 2 pick in this year's Entry Draft, on the Bruins' final chance as the Panthers rallied for a 3-2 victory Saturday night.
Boston carried a two-goal lead into the third period on the strength of tallies by Seguin and Horton, but Florida forced overtime when Radek Dvorak and Kenndal McArdle beat Tuukka Rask.
Patrice Bergeron led off the shootout with a goal for the Bruins, but Santorelli -- who is 3-for-3 career during the regular season in the penalty-shot tiebreaker -- answered immediately for the Panthers.
Clemmensen then denied Ryan Spooner, the Bruins' 2010 second-round pick, and Seguin, with Stillman scoring in between to give the Panthers the win.
Seguin opened the scoring 1:20 into the second period, scoring off assists from captain Zdeno Chara and veteran linemate Mark Recchi.
"I just received the pass and I wanted to get it off as quick as I could because I knew the goalie would be challenging," Seguin said.
Horton, acquired as part of a trade that saw Boston send defenseman Dennis Wideman to Florida, doubled the lead for his new club at the 11:51 mark.
Marty Reasoner drew primary assists on Dvorak's goal at 2:20 and McArdle's score at 8:46 that drew the Panthers even.
"We had a lot of unforced errors," Boston coach Claude Julien said. "We had some guys who didn't have real good games tonight -- we're talking about veterans, mostly. A lot of the young guys did some good things tonight and you try to take the positive out of it."
Rangers 5, Devils 4 (OT)
Michael Del Zotto scored New York's fourth power-play goal of the night 52 seconds into the extra period as the Rangers rallied from a pair of two-goal deficits for their second overtime win over the Devils in three nights.
New Jersey goalie Johan Hedberg lost his stick attempting to sweep the puck off a New York skater's stick in the sequence leading up to the winning goal. Devils defenseman Anton Volchenkov gave Hedberg his stick, essentially giving the Rangers a 4-on-2 advantage, and Ryan Callahan worked the puck into the left circle for Del Zotto, who lifted the puck over a lunging Hedberg.
Del Zotto finished with a four-point night, adding three assists, while Callahan and Ruslan Fedotenko each registered a goal and two assists for the Rangers.
"The chances we did have, we capitalized on," Del Zotto said. "Four power-play goals like that is huge. Hopefully, we can carry it into the season and keep it consistent all year. It's a big confidence boost. We kept it simple, put pucks on net and got some dirty goals."
Zach Parise set up goals by Ilya Kovalchuk, Andy Greene and Matt Taormina for the Devils, who also got a score from Brian Rolston.
Taormina ripped a shot from the blue line under the crossbar past Henrik Lundqvist with 6:49 left in the second period to give the Devils a 3-1 lead. Matt Gilroy's power-play goal 1:06 into the third drew the Rangers within one, but Rolston restored the two-goal advantage for New Jersey at 5:36 when he took a Greene pass and went in on a breakaway.
"We fought back in the third period," Gilroy said. "It was pretty cool. The power play, we haven't really worked on it and we had one in the first period that was pretty ugly. We settled down after that, got a few rushes, and it turned out pretty well."
The Devils continued to take penalties and the Rangers continued to click with the man advantage, as Artem Anisimov tipped in a Callahan shot with 9:59 left and Fedotenko forced overtime by beating Hedberg just 2:32 later.
"If you ask Johan, I'm sure he wishes he had a couple back," Devils coach John MacLean said. "He's finding his game. He's a veteran and sometimes it takes a little bit longer. It's one of those things. It's preseason. You let it go. We have full confidence in him."
Penguins 3, Blue Jackets 1
With the brand-new Consol Energy Center packed full of college students and youth hockey players, Pittsburgh received goals from Pascal Dupuis, Evgeni Malkin and Arron Asham, and 32 saves from goalie Marc-Andre Fleury.
Penguins coach Dan Bylsma gave the home fans a show by playing his two superstars on the same line -- Malkin, normally a center, played the wing on a line with captain Sidney Crosby. Malkin scored the go-ahead goal 2:47 into the third off assists from Andrew Hutchinson and Eric Tangradi.
Asham, a free-agent signing who played last season for the Eastern Conference champion Flyers, completed the scoring with 2:43 remaining. He finished with a goal and an assist, and Fleury did the rest.
"It's so good to see him play like that," Dupuis said. "We all know that he can play like that. He is ready to go. He came into camp in great shape and he is having fun out there right now. That makes for great confidence in him at the start of the season."
The Penguins teamed up with ImaginePittsburgh.com to give away every seat in the 18,087-capacity arena to the area’s youth hockey teams and college students as a part of the "Ultimate Home Game."
The Penguins donated 5,000 tickets to the Pennsylvania Amateur Hockey League as well as to the Penguins Kids Club and the Tickets for Kids Foundation, and 8,000 lucky college students won tickets by signing up at www.ImaginePittsburgh.com.
Defenseman Michael Ratchuck opened the scoring for Columbus in the first period and goalie Steve Mason made 25 saves.
Ratchuck made it 1-0 with 7:57 left in the first period, but Asham set up Dupuis on the tying goal with 3:12 left in the second.
Sabres 3, Maple Leafs 1
Ryan Miller played about half the game, stopping all nine shots he faced, and Buffalo received goals 1:47 apart in the second period by Rob Niedermayer and Tyler Ennis in winning on home ice.
The Sabres opened the scoring 9:17 into the first when defenseman Andrej Sekera took a Derek Roy feed and beat Maple Leafs goalie Jonas Gustavsson on a shot from the blue line that went through traffic and deflected in off the right post.
Ennis doubled Buffalo's lead with the prettiest goal of the night, corralling a bouncing pass by rookie Zack Kassian off a 2-on-1 break and backhanding the puck past Gustavsson at 9:47 of the second. Jussi Rynnas took over in the Toronto net shortly thereafter, and Niedermayer greeted him by making it 3-0 with 8:26 left in the period. Kassian forced a turnover leading to that goal.
"It felt great," Kassian said. "Hopefully, I impressed the coaches and hopefully I can get into another one and keep on improving every shift and every game."
A big hit he put on Toronto forward Christian Hanson early in the game didn't escape the notice of Buffalo coach Lindy Ruff either.
"I was pleasantly surprised," Ruff said. "He set a pretty good tone by knocking somebody six-to-eight feet backward and then on the offensive side did a lot of good things with the puck."
Miller stopped former teammate Clarke MacArthur off a 2-on-1 opportunity before departing in favor of Jhonas Enroth, who stopped 15 of 16 shots. Nikolai Kulemin got the Leafs on the board with 1:37 remaining in the second.
Senators 6, Canadiens 2
Jason Spezza took another step toward putting last season behind him, erupting for two goals and an assist as Ottawa made life difficult for Montreal goalie Carey Price.
Nick Foligno also scored twice for the Senators, Chris Neil had a power-play goal and Bobby Butler converted on a penalty shot against Price, who finished with 24 saves. He allowed four goals on just nine shots in his previous outing.
"They scored three power-play goals, one on the penalty shots and two gifts," said Canadiens coach Jacques Martin.
"Certain players didn't play well and there were some young guys who had a good showing, but this really demonstrates how important special teams are and we have to work on them."
Brian Maxwell and Tomas Plekanec had goals for the Canadiens, but Maxwell was also stopped on a penalty shot by Senators goalie Brian Elliott, who finished with 27 saves.
The Canadiens led 2-1 before Spezza scored with 4:27 left in the second period to start an outburst of five unanswered goals by the Senators. Spezza, who slumped to 23 goals during an injury-plagued 2009-10 season, caught Price by surprise with a shot from the left corner. Defenseman Sergei Gonchar drew an assist in his Ottawa debut.
Foligno put the Senators in front with 1:28 to play in the second, beating Price on a deke, and Butler made it 4-2 on a penalty shot with 34.1 seconds left after he was hauled down on a breakaway by Canadiens defenseman Josh Gorges.
"He's looked really good this training camp getting to loose pucks and winning battles," Ottawa captain Daniel Alfredsson said of Foligno. "The two goals he scored were unbelievable and I wish I could do that."
Stars 5, Blues 2
St. Louis had won its previous two games over Minnesota by a 10-1 margin, but facing the franchise formerly known as the North Stars, the Blues fell victim for a first-period blitz on Saturday.
Aaron Gagnon and Travis Morin scored 13 seconds apart and the Stars put up four goals in a span of 4:26 in cruising to victory.
After Gagnon beat Jake Allen on a wrister at 10:19 and Morin converted a rebound to give Dallas a 2-0 lead, Trevor Daley and Brenden Morrow quickly doubled the advantage. Daley lit the lamp at 13:15 and Morrow notched the first of his two goals on the night 90 seconds later.
The Blues were able to cut their deficit in half during the second, getting a power-play goal from Nikita Nikitin at 3:35 and a Stefan Della Rovere goal at 7:27 against Brent Krahn, who stopped 19 shots. He is battling veteran Andrew Raycroft for the backup goalie spot behind starter Kari Lehtonen.
"I thought he was good," Stars coach Marc Crawford said. "I thought he made some good saves with his size and showed himself to be big, and I thought he withstood the battles in front of the net, and that was a question for us tonight. He got a really good mark for that. He’s still got a ways to go in his puck-handling ability, for sure."
Morrow, the Stars' captain, completed the scoring with 1:34 left in the second. He gave credit to linemates Adam Burish and Mike Ribeiro for his big night.
"I think the combination was pretty good tonight," Morrow said. "On both my goals, Burish was driving the net or had already driven the net and was planted in front, and then we all know the plays that Ribs can make with the puck, so it was a good fit. Tonight it worked, it felt good to get rewarded for hard work."
Hurricanes 1, Thrashers 0
Jeff Skinner might not have gotten the hype of some of the top picks in this year's draft, but Carolina's first-round selection is stating his case to make the opening night roster.
Skinner put a wrist shot past Chris Mason 1:17 into the third period and Cam Ward stopped all 32 shots against him as the Hurricanes won in Atlanta.
"It was a good game," Mason said. "I thought we played back and forth, and our guys played really hard. This was a typical preseason game. We still have some things to work on, but I thought the guys really worked hard. We're picking up some of the systems here, but we still have work to do."
Erik Cole drew the lone assist on the goal by Skinner, a 50-goal scorer last season for Kitchener of the OHL who was taken with the No. 7 pick.
Moments after the goal, Hurricanes forward Sergei Samsonov went into the boards head-first after a hit from Dustin Byfuglien of the Thrashers and had to be taken off on a stretcher. He was taken to a local hospital for observation. The team said Samsonov had full feeling in all his extremities.
Flyers 3, Wild 2 (SO)
Nikolai Zherdev scored in regulation and added the only goal of the shootout for Philadelphia, which also received a score by Darroll Powe and 26 saves from Russian rookie Sergei Bobrovsky in net.
Casey Wellman and Chuck Kobasew had the goals for Minnesota. Wellman had the final opportunity to extend the penalty-shot tiebreaker, but he was denied by Bobrovsky, who also stopped Wild captain Mikko Koivu and Martin Havlat.
Bobrovsky made 18 saves during regulation and overtime as he battles for the backup goaltending spot on Philadelphia behind veteran Michael Leighton.
Capitals 2, Predators 1
It was a big night for Washington defenseman Mike Green, who netted a power-play goal and set up the winning score by Jay Beagle 6:47 into the third period as the Capitals won in Nashville.
Dany Sabourin stopped all 11 shots he faced in relief of Michal Neuvirth, who was also strong in making 14 saves.
With new Predators captain Shea Weber in the penalty box early for cross checking, Nicklas Backstrom set up Green for a shot past Pekka Rinne at 3:21 of the first period. Rinne stopped seven shots before giving way to Anders Lindback.
Matt Halischuk, acquired over the summer from New Jersey for former Nashville captain Jason Arnott, got the equalizer at 7:25 of the second.
Flames 5, Lightning 4 (SO)
Coming off a disappointing season, Ales Kotalik had a big night to help Calgary edge Tampa Bay.
Kotalik scored a goal and two assists, then added the shootout winner for the Flames, who also received a pair of power-play goals from rookie defenseman T.J. Brodie.
Once a 25-goal scorer for Buffalo, the 31-year-old Kotalik slipped to 11 goals and 27 points while splitting last season between the Rangers and Flames. He had only 3 goals in 26 games after Calgary acquired him.
"He's been a driven guy," Flames coach Brent Sutter said. "He knows he's got confidence from his coaching staff that we believe in him and he can go out there and get the job done for us."
Kotalik and Mark Giordano both assisted on the goals by Brodie, which came at 6:59 and 10:20 of the first period and turned a 1-0 deficit created by a Vincent Lecavalier score 27 seconds into the game into a 2-1 lead for the Flames.
"I'm just out here working hard and trying to get a spot somewhere whether it's here or Abbotsford (with the Heat of the American Hockey League)," Brodie said.
Craig Conroy made it 3-1 at 8:30 of the second, but just 75 seconds later Simon Gagne scored his first goal since the Flyers traded him to the Lightning during the offseason.
Kotalik restored the Flames' two-goal cushion 6:33 into the third, but the Lightning forced overtime on power-play goals by Lecavalier and Steven Stamkos. The NHL leader in power-play goals a season ago with 24, Stamkos netted the equalizer with 1:12 left in regulation.
"The only disappointing part is we didn't start very strong," said Martin St. Louis, who had a pair of assists in the contest.
"We kind of gave them a head start. We were able to fight back. If we play like we played in the second half of that game, I don't think it would have been the same result. It's a 60-minute game. We've got to find a way to come out of the gate harder than that."
Canucks 4, Ducks 1
Roberto Luongo appeared to be in top form. So did the Sedin twins.
Henrik Sedin and Daniel Sedin each registered a goal and an assist, and Luongo turned aside 28 shots as Vancouver won its first game of the preseason after three defeats.
Also scoring for the Canucks were Guillaume Desbiens and Jordan Schroeder. Veterans Brendan Morrison and Peter Schaefer, in camp on a tryout basis, each picked up an assist.
Luongo carried a shutout into the third period before ex-Canuck Josh Green beat him with 7:18 remaining to get the Ducks on the board. Jonas Hiller finished with 21 saves.
Coyotes 2, Sharks 1
Radim Vrbata scored a pair of power-play goals as Phoenix edged San Jose on home ice with each team splitting their squads.
Vrbata opened the scoring with 1:53 left in the first period. After the Sharks drew even at 2:43 of the second on a Jamie McGinn goal, Vrbata capitalized midway through the third for the winner. Cory Quirk was in the box for slashing when Vrbata beat Thomas Greiss with 9:19 remaining to put the Coyotes in front to stay.
Ilya Bryzgalov finished with 21 saves for Phoenix, while Greiss stopped 28 shots for San Jose.
Sharks 3, Coyotes 1
Patrick Marleau and Sean Sullivan scored 57 seconds apart early in the third period as San Jose beat Phoenix in the other half of Saturday's split-squad action.
Dany Heatley also scored for the Sharks and Antti Niemi stopped 18 of 19 shots over the first two periods before Alex Stalock made five saves in a scoreless third for the victory.
Coyotes captain Shane Doan started the scoring at 10:45 of the first with a power-play goal. Matt Climie went the distance in net, making 20 saves.
Marleau and Heatley each finished with a goal and an assist. Marleau set up Heatley's game-tying score 4:22 into the second, then put the Sharks in front at 4:32 of the third when he found himself in the right place to convert the rebound of a Joe Pavelski shot. Marleau tipped the puck past Climie for his first goal of the preseason.
On an ensuing 3-on-2 rush, Heatley fed the puck over to Sullivan for the insurance goal.
"No matter what game it is, you want to win it and obviously get that feeling in this room," Marleau said. "We came out tonight and I think we were playing a little bit better game. We stayed out of the penalty box, which seemed to help. The more we can stick with the system, the better we'll be."
Material from wire services and team online media was used in this report.