Chicago and Los Angeles each lost in the first round this season. The Blues knocked out the Blackhawks, the defending Stanley Cup champion, in a seven-game series.
The Blues and Stars played five times in the regular season and there was little to separate them.
St. Louis won four of the games, two in overtime and another in a shootout. Each team won a game 3-0.
Left wing Jamie Benn and defenseman Alex Goligoski led the Stars with five points each. Benn had four goals and 10 points in the first round, when the Stars defeated the Minnesota Wild in six games.
Defenseman Kevin Shattenkirk led the Blues with five points against the Stars, and forwards Vladimir Tarasenko and Paul Stastny had four points each. Tarasenko had four goals and two assists in the first round, finishing with one point fewer than leading scorer Jaden Schwartz.
These teams last played in the Stanley Cup Playoffs in 2001, when the Blues won a four-game sweep in the second round.
Video: MIN@DAL, Gm5: Ja. Benn beats Dubnyk with nifty move
Stars: Dallas center Tyler Seguin was able to play only in Game 2 of the first round because of the aftereffects of March surgery to repair a partially torn Achilles tendon in his left foot. Seguin has not practiced for the past week and didn't travel to Minnesota for Games 3, 4 and 6, so his status for the second round remains uncertain.
But the Stars did fine offensively in the first round without him. Second-line center Jason Spezza had nine points (four goals, five assists).
"Just trying to be hard on pucks, try to be a big part of the power play," Spezza said after Game 6. "I just have a good role here, feel comfortable, really enjoy my teammates right now. I think we've got a good thing going here."
Playoff veterans Patrick Eaves (five points) and Patrick Sharp (four points) contributed in the first round. Cody Eakin had four points, and Ales Hemsky and rookie Mattias Janmark each had three. Rookie Radek Faksa scored the game-winning goal in Game 1.
Vernon Fiddler had one point in the series but delivered his standard gritty play and won plenty of faceoffs. Antoine Roussel scored an odd goal in Game 2 but mostly helped the Stars by being an irritating presence against the Wild.
Colton Sceviour scored against Minnesota and made plays which didn't show up on the stat sheet but were invaluable. Valeri Nichushkin finished with no points, but Stars coach Lindy Ruff said he liked his size and presence in the five games he played.
In Game 6, Ruff played veteran Travis Moen, a member of the Anaheim Ducks' 2007 Stanley Cup championship team, for the first time in the series with Nichushkin scratched.
"Here's a veteran guy that has played well for us," Ruff said of Moen after Game 6. "He's real heavy on the puck, real reliable. He's played well."
Video: STL@CHI, Gm4: Tarasenko sparks Blues with two goals
Blues: St. Louis got great work from its "STL Line" of Schwartz, Tarasenko and Jori Lehtera against the Blackhawks in the first round. The line combined for 17 points in seven games, with Schwartz leading all scorers with seven points (three goals, four assists). Lehtera scored in the 3-2, Game 7 victory.
Center Paul Stastny and linemates Troy Brouwer and Robby Fabbri were given the assignment of blanketing any line that included Chicago center Jonathan Toews, and from Game 5 on, had to deal with wing Patrick Kane. Early in the series, Blues coach Ken Hitchcock switched Fabbri with Alexander Steen, moving Fabbri to a line with Patrik Berglund and David Backes before Fabbri rejoined Stastny and Brouwer, the Blues' hottest point-producing line in the last month of the regular season.
Brouwer scored his first Game 7 goal, the game-winner in the third period, and Stastny and Fabbri assisted. Fabbri led the line with a goal and four assists.
"It means a lot to me; it means a lot to the franchise," Brouwer said of the victory against the Blackhawks. "It's been a long, tough season. To see us get rewarded like this, especially against a division rival like the Blackhawks in such dramatic fashion, there's all smiles around."
Kyle Brodziak was a force centering the fourth line with Scottie Upshall and to start the first round series, Ryan Reaves, and then Steve Ott, who returned after missing 57 games with torn hamstrings and colitis.
Stars: Ruff played seven defensemen in the first round but mostly used a six-man core of Jason Demers, Alex Goligoski, Stephen Johns, John Klingberg, Johnny Oduya and Kris Russell.
The seventh defenseman, Jordie Benn, played in Game 3 when Russell was out with an illness.
Klingberg had three points in the series, all in Games 5 and 6.
Ruff juggled his pairs at different points against the Wild, but the six-man group that played the majority of the games are the players he trusts most. Should one of them lose form or sustain an injury, Jordie Benn, Patrik Nemeth and Jamie Oleksiak are capable of stepping in.
Two members of this group have won the Stanley Cup: Goligoski with the Pittsburgh Penguins in 2009 and Oduya with the Blackhawks in 2013 and 2015.
Blues: Alex Pietrangelo had arguably his best Stanley Cup Playoff series since arriving in St. Louis in 2012.
He was tied for second on the Blues with six points (one goal, five assists), but his poise with the puck gave them a formidable shutdown pair against the Toews line. He will have to do so again against Jamie Benn.
"I've just been trying to lead the way on the back end there," Pietrangelo said. "I've been given a lot of opportunities by the coaching staff to go out there, make plays and make an effort to lead the charge. I'm feeding off my teammates. They've been great."
Kevin Shattenkirk had a tough series against the Blackhawks, but he had to play a large portion of the series as a right-hander on his off-side with rookie Colton Parayko. But Shattenkirk, who had a goal and three assists, returned with rookie Joel Edmundson to close out the series, and Parayko was paired again with Carl Gunnarsson, who seems to play his best hockey when matched with him.
Video: MIN@DAL, Gm2: Lehtonen denies mad scramble in front
Stars: Ruff almost evenly divided starts between Kari Lehtonen and Antti Niemi during the regular season, but in the first round Lehtonen started four games and performed well, going 3-1 with a 2.27 goals-against average, .911 save percentage and one shutout.
Niemi delivered mixed results in two starts against the Wild, going 1-1 with a 3.36 GAA and .870 save percentage.
Lehtonen was in net for the series-clinching, 5-4 win in Game 6 at Xcel Energy Center on Sunday.
"I thought our goaltending was good," Ruff said. "It gave us a chance to win the series."
Lehtonen started Games 1, 2 and 3, but Niemi replaced him for Game 4 after the Stars lost. Niemi started again in Game 5, but after the Wild won 5-4 in overtime to force Game 6, Lehtonen was in goal.
The rotation worked well this season and again in the first round, but will the Stars continue with the arrangement? Or does Ruff now decide to choose one starter to stick with?
Video: STL@CHI, Gm4: Elliott robs Kane on breakaway
Blues: Brian Elliott had a 2.40 goals-against average, .929 save percentage and stopped 236 of 254 shots against the Blackhawks. He had 30 or more saves in six of the seven games, with a high of 44 in Game 3.
"When you want to go for a championship, you usually have to beat out the champ," said Elliott, who won his first Game 7 against the Blackhawks.
Jake Allen is a formidable backup, but it's quite evident Elliott has shaken off postseasons past when he was overlooked.
"I'm not trying to prove anything to anybody right now," Elliott said.
Stars: The first-round win was Ruff's first playoff series victory since the 2007 Eastern Conference Semifinal, when his Buffalo Sabres eliminated the New York Rangers in six games.
Ruff lost three straight times in the first round, twice with the Sabres, and two seasons ago in his first with the Stars.
One reason Ruff was able to reach the second round was an experienced veteran core, including Oduya and Sharp, offseason additions who won the Stanley Cup a combined five times with the Blackhawks.
"We're a relatively inexperienced team together and I think you can see some of the guys that have played [in this environment]," Spezza said after Game 6. "Patrick Sharp was great [Sunday]. Johnny Oduya was great. You can see those guys, they know how to play these games."
Blues: Hitchcock won his second playoff series with St. Louis in five seasons.
With a one-year contract, a fourth straight first-round exit would likely have meant the end of his tenure. But as was the case for much of the regular season, the 64-year-old and his staff held a tight group together through some adversity.
And for the first time since Hitchcock left Dallas with his only Stanley Cup (1999), he will coach against his former team in the playoffs.
"Maybe people will start talking about what a unique team we have," said Hitchcock, who is 14-20 in the playoffs with the Blues. "We have a unique team. We have a team that's a team in every sense of the world. This is the most together group of athletes I've ever coached in a long, long time. Who knows what happens, but we're very much a team in every sense of the world.
"... For everything that we've done collectively together and how close these guys are, I wanted them to have success and they did it. So the naysayers, they need to take a day off because we can celebrate for a day, and then you can all start bashing us."
Video: MIN@DAL, Gm1: Eaves jams home rebound for PPG
Stars: The Dallas power play, fourth in the regular season at 22.1 percent, finished 4-for-19 (21.4 percent).
The Stars were 1-for-13 in the first three games against the Wild. In Game 4, they were 2-for-2, and during the last three games went 3-for-6.
The Dallas penalty kill had a success rate of 82.3 percent during the regular season, which dipped to 75.0 percent against Minnesota.
Video: STL@CHI, Gm3: Parayko scores on blistering slap shot
Blues: The power play went 5-for-18 (27.7 percent) against Chicago, but the penalty kill will have to be better than it was against the Blackhawks, who were 6-for-19 (31.5 percent) on the power play.
Schwartz scored three of the Blues' five power-play goals; Tarasenko and Parayko had the others.
The Blues are not afraid to use either of their power-play units. Tarasenko, Steen, Shattenkirk, Backes and Schwartz make up the first; Pietrangelo, Parayko, Stastny, Brouwer and Fabbri are the second group.
Video: NJD@DAL: Nichushkin opens the scoring on pretty move
Stars: Valeri Nichushkin -- The 10th pick of the 2013 NHL Draft was a healthy scratch in Game 6 when Ruff went with Moen because he has more playoff experience. But Ruff's postgame remarks about Nichushkin show he still has faith in the 21-year-old.
"Val is working extremely hard," Ruff said. "There hasn't been a lot of good go for him, he hasn't had a lot of breaks. He hasn't had an alley-oop, he hasn't had a redirection, he hasn't had pucks go off him. But every shift I put him on the ice that kid works as hard as he can."
Nichushkin did not have a point in the first round, but Ruff said he feels a breakout is close.
"Right now things haven't come his way but I really believe they will," he said.
Video: STL@CHI, Gm6: Tarasenko goes top-shelf to pad lead
Blues: Vladimir Tarasenko -- The right wing had two goals and two assists in five games against the Stars in the regular season, and has eight goals and five assists in 14 games against Dallas.
Much was made of Tarasenko's limited minutes in the series against Chicago -- he averaged 17:02 per game -- but with Hitchcock's style of using four lines, and other players' ability to step up against the Blackhawks, the minutes were spread out and matchups were a priority. However, with a more wide-open style expected, Tarasenko should have a plethora of opportunities to score against Dallas.
WILL WIN IF …
Stars: Dallas can clean up some of the issues that came up in the first round, the two biggest being slow starts and blown leads.
The Stars started slowly most notably Game 5, when the Wild took a 2-0 lead in a game they won 5-4 in overtime. The Stars started much better in Game 6, building a 4-0 lead, but they had to hold on for a 5-4 win to clinch the series.
Blown leads were a huge issue for the Stars last season and a big reason they missed the playoffs.
Blues: St. Louis can expose Dallas' defense and uncertainty of who will play in goal.
The Blues have balanced offense and were able to expose Chicago's defense while forcing defensemen Duncan Keith, Brent Seabrook and Niklas Hjalmarsson to play heavy minutes.
The Blues like to wear down the defense with an aggressive forecheck that forces turnovers.
St. Louis averaged 2.71 goals per game against the Blackhawks, but there is the opportunity to increase those numbers against the Stars. Twelve Blues scored in the first round.