Seguin's natural hat trick plus an assist, all in that second period, led Dallas a 5-1 victory over the Philadelphia Flyers.
It wasn't clear whether the third goal, on a drive from the top of the right circle had deflected off of linemate Jamie Benn's stick.
Benn said, ''I knew right away it wasn't me that tipped it in. I pointed right at Seguin, and he pointed at me. I said, `No, it wasn't me.'''
Seguin's first goal came in on a 2-on-1 rush with Benn to tie the score at 1-all at :39 seconds of the second period.
''I just felt good for both Bennie and I. It's no secret that we've been getting a little frustrated,'' he said.
The Stars then scored three times in a span of 1:02 to break the game open.
''You really don't realize how quickly things happen until it's too late,'' Mason said. ''You let three goals in a game, let alone in one minute, definitely does not bode well.''
Winning goalie Dan Ellis, who made 27 saves, liked what he saw as the score jumped from 1-1 to 4-1.
''I was happy. Who wouldn't be? Any time you can kind of relax by getting offensive support that helps,'' Ellis said.
Seguin leads the Stars with 15 goals. The hat trick was his second this season and third in his 4-year career. He was in his second game back after missing two because of concussion-like symptoms.
He and Benn had been frustrated during Seguin's first game back Thursday at Toronto. They combined to put 15 shots on goal, but didn't score, in a 3-2 overtime loss.
''You make mistakes with Seguin and Benn on the ice and you're going to be in trouble,'' Philadelphia head coach Craig Berube said.
Ellis evened his record at 3-3, including two victories in a row. He had not allowed fewer than three goals in a complete game this season. Ellis said he felt better with more frequent playing time (three games in 15 days).
''I've definitely played a few more games recently. That definitely gives you a feel for the game.''
Dallas head coach Lindy Ruff said, ''He played an excellent game. He's won the last couple. That gives me confidence to keep him in there.''
The Stars, who had lost six in a row against the Flyers dating back to 2008-09, improved to 14-9-5; Philadelphia dropped to 13-14-2 and 2-2 during a six-game road trip.
The Flyers played most of the game down a skater after center Zac Rinaldo drew a game misconduct penalty at 1:15 of the first period.
Dallas also was a skater short after center Vernon Fiddler sustained an upper-body injury in the second period.
Rinaldo had pounced on Stars left wing Antoine Roussel as he slid past the net, and received 27 minutes in penalties - a 2-minute instigator minor, a 5-minute major for fighting, a 10-minute misconduct for being the aggressor and the 10-minute game misconduct. Roussel was not penalized.
Said Flyers head coach Craig Berube: ''He went out there and punched him (Roussel) in the head a few times. Stupid.''
The minor and the major gave Dallas 7 power-play minutes. The Stars had several chances against Mason during that time, but couldn't score.
For the game, Dallas' power play was 0 for 5, dropping it to 1 for 42 (2 percent) at home this season.
Ruff said, ''It looked pretty good, but we didn't score again.''
The penalty-killing effort may have taken a toll on the Flyers.
''Seven minutes, that's a lot of minutes,'' Philadelphia center Claude Giroux said. ''Some of the guys were playing a little bit too much.''
Philadelphia took a 1-0 lead at 18:51 of the first when Andrej Meszaros scored his first goal as Stars defenders scrambled to try to protect Ellis.
Later, it was Flyers defenders breaking down.
''Without Mason making six or seven unbelievable saves, it could have been 9-1 after the second,'' the Flyers' Scott Hartnell, playing in his 900th NHL game, said.
Ray Emery replaced Mason in goal to begin the third period.
NOTES: The teams hadn't met in nearly two years, since Philadelphia's 4-1 victory at Dallas Dec. 21, 2011. ... On their eventful trip, the Flyers endured a bumpy flight into Dallas-Fort Worth Thursday. On Friday, they didn't practice because an ice storm knocked out the power at a rink in Farmers Branch, Texas. ... Icy roads held the attendance down to a season-low 8,647. The Stars allowed fans at the topmost level to move closer to the ice. Ellis said, ''It was like they turned it into general admission.'' . Flyers forward Vincent Lecavalier missed his third consecutive game because of back spasms. For Dallas, defenseman Trevor Daley missed his first game after going on injured reserve for an ankle injury sustained Thursday at Toronto. Stars left wing Ryan Garbutt returned after missing the Toronto game because of an ankle injury. ... Entering the game, the Stars were 1-2-4 in their previous seven home games.