PITTSBURGH -- The Dallas Stars had trouble controlling their emotions, giving up two power-play goals during an undisciplined first period.
A late disallowed goal in the third allowed the Stars to channel their frustration into a come-from-behind win.
"Crazy is a pretty good word," Seguin said. "Desperation, compete by everybody. We really wanted that game."
Seguin's goal capped a furious comeback as Dallas scored twice in the final 2:57 to win its second straight and snap a six-game losing streak in Pittsburgh. Jamie Benn and Antoine Roussel also scored for the Stars, who wrapped up a three-game road trip with a win in Pittsburgh for the first time since Dec. 23, 2000.
"We didn't get a point out of that and it's a little frustrating," Crosby said.
Dallas, trailing 2-1, thought it had the tying score with 3:33 left, but Jason Spezza's would-be goal was waved off after it was ruled that Seguin interfered with goalie Marc-Andre Fleury during a partial breakaway.
"Obviously a disallowed goal is a good bounce, but we didn't take advantage of it," Crosby said.
The Stars did, tying the game seconds later, as Benn got his second of the year when he slammed home a rebound from the top of the crease.
Seguin scored the game-winner after Crosby was whistled for tripping with 10 seconds left. He took a pass at the point from Spezza and wristed a shot that caromed off Fleury's blocker and into the net.
Fleury finished with 25 saves, while Kari Lehtonen stopped 27 shots for Stars.
Penguins forward Pascal Dupuis left the game on a stretcher in the second period.
Dupuis remained on his knees in discomfort and threw off his gloves, shaking his hands before play stopped with 6:58 remaining in the period. He was tended to while on his back for several minutes and gave a `thumbs-up' to the crowd while leaving the ice.
"He had some numbness in his arm and it was coming back, so that's a real positive sign, but I haven't heard anything more," Penguins' coach Mike Johnston said.
Dupuis tore the ACL in his right knee last December, costing him the final 43 games of the regular season. He had four points in the Penguins' season opener last Thursday.
"As difficult as it is, you have to go out and play," Crosby said. "I don't think we necessarily let down because of that. They picked it up."
Seguin, Benn and Spezza led the way.
Seguin had a hat trick during a 4-2 win against Columbus on Tuesday, while Benn notched four points, but Spezza struggled entering Thursday's game with just one assist.
That changed in the final three minutes against the Penguins.
Spezza, who spent 11 years with Ottawa -- the last one as captain -- before he was traded to Dallas in the offseason, helped on the final two goals, notching the primary assist on the game-winner.
"That's the type of leadership we're looking for," Stars coach Lindy Ruff said. "I thought he did a lot of good things and was there to help us."
The Penguins' power-play went 2 for 4 with all four attempts coming in the first period. Also, all of their nine shots in the opening period came with the man advantage.
After going 3 for 5 during a win Saturday in Toronto, Pittsburgh is 6 for 13 on the power play this season. The Penguins' penalty kill, after allowing five goals on 11 chances in their first two games, was perfect until Seguin's game-winner.
Dallas entered the game with a goal in eight power-play opportunities and was 0 for 3 until Seguin scored. The Stars previously missed out on 27 straight power-play opportunities in Pittsburgh, last scoring during an 8-2 victory in 2000.
"That one at the end, you can scratch off the other ones because that was the biggest one and it counted," Ruff said.
Trailing 2-0, the Stars regrouped after a sloppy opening period, cracking the scoreboard a little more than six minutes into the second.
Vernon Fiddler's behind-the-net pass went through the crease to the top of the right circle where Roussel fired it past Fleury.
The Penguins won eight of the previous 10 meetings against Dallas. Johnston missed out on becoming the second coach in Penguins' history to win his first three games. Evgeni Malkin passed Rick Kehoe for fourth on the team's all-time points list. ... Penguins' F Nick Spaling appeared in his 300th game. ... Pittsburgh continues a three-game homestand Saturday against the New York Islanders, while Dallas returns home against Philadelphia.