Boston is 6-15-3 when trailing after two periods. Dallas is 29-2-3 when leading after two.
"This one is a real burner," Stars coach Ken Hitchcock said. "We've got to figure out … we've got 48 hours to get ready to play again."
Bruins coach Bruce Cassidy saw both good and bad in the third-period rally after allowing a shorthanded goal in the final minute of the second period.
"It can become a double-edged sword," he said. "Maybe you lose a bit of that urgency early on, thinking, 'We can get it back.' You have to be careful, but I think it helps mentally knowing you've done it before."
Marchand cut the Stars lead to 2-1 at 1:17 of the third period when he was credited with the goal when a shot by Pastrnak caromed off his left knee at the top of the crease.
The play was close enough to Lehtonen for the Dallas bench to view a replay and consider a challenge.
"We had six looks at it," Hitchcock said. "We also had the call from in the video room here. So, otherwise, we would have made the call."
Schaller tied it 2-2 with a shorthanded goal at 9:47, skating in alone off a pass from Marchand. He lifted the puck into the net after Lehtonen committed and fell forward.
"It was bobbling a little bit, so I thought maybe the goalie would come out a little bit," Schaller said. "I thought if I gave him a little flinch he would react to it. And he did, and I was able to sneak it in."
Lindell ended a 20-game goalless drought 2:26 into the first period to give the Stars a 1-0 lead. Curtis McKenzie passed from behind the goal line to Lindell at the left point, and his wrist shot beat Rask.
Benn tied it 2-2 with a shorthanded goal with 38 seconds left in the second period. Bruins defenseman Matt Grzelcyk fell at the left point, allowing the puck to slide out of the offensive zone, and Benn skated in and slid a backhander past Rask.
"You would think it was a game-changer," Cassidy said. "You go in between periods and you just have to take a deep breath."
