Rust scored into an empty net at 18:31 of the third period for the 4-2 final.
Bruins center Patrice Bergeron left the game at 8:44 of the third with an upper-body injury after colliding with Crosby and hitting the boards. Cassidy had no update.
Bruins forward Brad Marchand was assessed a two-minute roughing penalty and five-minute match penalty for attempt to injure with 25 seconds left in the third after an exchange with Jarry. Marchand punched Jarry and later poked him in the mask with his stick.
"I think it's just the heat of the moment," Jarry said. "I think everyone's battling hard out there, he's just trying to get the puck to the net, and I think our team did a great job. It's part of the game, and it stays on the ice."
Cassidy said, "Honestly, that's lack of discipline on Brad's part in that situation. I just watched the replay at the end. It looks like some words were exchanged. … Brad's a leader on our team and he needs to control his emotions in that situation."
NOTES: It was Heinen's first game against the Bruins since they traded him to the Anaheim Ducks on Feb. 24, 2020. He played his first four NHL seasons (2017-20) for Boston, scoring 103 points (34 goals, 69 assists) in 220 games. His two goals Tuesday were the fastest by a Penguins player since Martin Straka scored twice in seven seconds during a 2-2 tie against the Edmonton Oilers on Feb. 11, 2000. … Pastrnak scored the first goal of the game for the 52nd time, tied with Marchand for the most in the NHL since he debuted in 2014-15. Pastrnak scored two goals for the second straight game and has scored 16 in his past 16 games. The goals have come since Jan. 1 (18 games) and are the most in the NHL in that span.