Horton’s second goal, his sixth of the season, came 2:33 into the final period when he redirected a shot by Zdeno Chara from the left point. Dougie Hamilton picked up his second assist of the game on the goal.
"I didn’t know the goalie was out that far," Horton said. "I don’t know if someone pushed him out but he was out far. I got a tip to the net and the net was wide open.
"It was a great play by Zdeno. Goalies come out so far to challenge now and try to take away the angle and you get the back-door plays and the rebounds. That’s where you score a lot of the goals."
The teams exchanged goals in the second period, with Cory Conacher briefly knotting the score at 2-2 with a wrist shot from the left faceoff circle that beat Bruins goaltender Tuukka Rask cleanly. Steven Stamkos and Teddy Purcell each got their second point of the game with assists. For Purcell, it gave him seven points over his past five games.
Tampa Bay was surging at the midpoint of the period but Boston turned the momentum back when Marchand found a bouncing puck in the slot and put it behind Lightning netminder Anders Lindback to regain the lead, 3-2. Marchand's goal was assisted by Tyler Seguin and Bergeron, and gave the left wing nine goals for the season, good for the team lead.
It was Marchand's goal that turned the tide, according to Lightning coach Guy Boucher.
"We could have won this game; we could have tied this game," Boucher said. "It was a really close game. It's too bad on the third goal, we blocked a shot and it bounces right to their stick and they put it in. So that was a downer there."
It didn't take long for the Bruins to get on the scoreboard -- 71 seconds after the opening faceoff, to be exact. Lindback kicked a rebound of Hamilton's shot from the blueline right to Horton, waiting to his right to hit an open net.
The Bruins were right back at it 2:39 later. Lightning defensemen Eric Brewer and Victor Hedman both got caught behind the goal line while Marchand was able to come away with the puck. His pass to Bergeron led to a one-timer and Bergeron's third goal of the season.
Boston's two goals came on its first four shots.
"We had a good start and that carried us through the game," Horton said. "It feels a lot better when you're playing with the lead."
Stamkos got one goal back when Purcell battled for the puck in the slot and slipped it behind him to Stamkos in the high slot. His snap shot beat Rask just under the crossbar. The goal was No. 11 on the season for Stamkos, who has four over the past three games.
Rask stopped 24 shots for the win, his eighth of the season, including a cross-crease dive that denied Benoit Pouliot on what looked like a sure goal.
"I saw him (Pouliot) there," Rask said. "I saw him sneak in the back door and then (Martin) St. Louis had a little time to think about what he does. I just tried to get there as quick as I could and I think it hit my stick."
There were three penalties whistled in the game, all against the Bruins. The Boston penalty kill was perfect, shutting out the Lightning while holding them to three shots on net with the extra attacker. The Bruins have now disposed of 17 consecutive short-handed situations without allowing a goal.
Boston began the third period a man short for 1:35.
"We knew coming out in the third that we needed a big penalty kill and not to play on our heels," Bruins coach Claude Julien said. "Our guys responded well to that tonight, and the penalty kill against a pretty good power play did a great job. I thought we had managed to not let them spend too much time in our end, so good job on the PK again."
Julien stopped short of calling the win Boston’s most complete game of the season.
"I didn't think we managed the puck really well for two periods," he said. "I thought the effort was there but we turned a lot of pucks over just by not managing it well. Considering that it was really humid in this building tonight and you could see, when you’re not use to playing in those conditions, our guys after two periods looked a little tired. I wanted to stretch out those four lines as long as I could.
"Effortwise, I have no complaints, but analyzing the game, I thought we managed the puck a lot better in the third period than we did in the first two."
Boucher was looking to see how his club matched up against a solid team like Boston, and he pronounced himself pleased.
"To be honest with you, I wanted to see the intensity and physicality against a team like that," Boucher said. "They come at you with four lines, very solid, and I wanted to see if we could sustain the work ethic and the desire to win battles and get to their net and defend in front of our net, and we did that all game. There was no lull. There was no down at any moment of the game, so that was good to see."
Lindback finished with 22 saves as his record went to 7-4-1.
Boston (10-2-2) moves on to face the Florida Panthers on Sunday. Tampa Bay (8-7-1) heads out on a two-game road swing, beginning Saturday against the Carolina Hurricanes.