"It shows a lot of guts and we're all happy that, first of all, he's OK, and for him to respond like that it's pretty amazing," Crosby said.
Letang passed a concussion protocol after he had his nose broken on a hit by Max Pacioretty with 3:14 to go in the third.
"They were just happy to see me get back in the game," Letang said. "They didn't say much other than, 'Let's go! Get one!'"
Price threw away his stick and defenseman Hal Gill, one of the Canadiens' alternate captains, argued with referee Dan O'Rourke -- to no avail -- that his goalie had covered up the puck on the play.
"It's really disappointing it ended that way," Montreal coach Jacques Martin said.
Jordan Staal drew Pittsburgh even at 3 with 4:30 left in regulation. Staal drove in on Price after taking a pass from Evgeni Malkin and stickhandled to freeze the Montreal goalie before flipping a shot into the top left corner.
Crosby, who had three assists in Pittsburgh's 6-3 win over Ottawa on Friday, got his eighth point in four games back from concussion-like symptoms that sidelined him for the better part of 11 months with an assist on Evgeni Malkin's goal 21 seconds in.
Letang was bleeding from the nose and had blood on his visor after he was run over by Pacioretty while following through on a slap shot inside the Montreal blue line.
Pacioretty suffered a broken cervical vertebra on a devastating hit by Boston's Zdeno Chara on March 8. He missed the rest of the 2010-11 regular season and playoffs.
"He came to apologize," Letang said. "It was a great gesture by him."
Guided by Matt Cooke and Dupuis as he skated off the ice to the dressing room, Letang returned for overtime.
"I feel terrible that he got hurt but I'm thankful that he came back," Pacioretty said.
No penalty was called on the play.
"I was surprised, yes," said Penguins coach Dan Bylsma, who expects that the league will review the hit.
"I thought it was a good hit," Martin said.
Crosby picked up his sixth assist when Malkin scored during a delayed penalty call 21 seconds in. Malkin put the puck past Price for his eighth goal shortly after Crosby drove the net to draw a call against Canadiens defenseman Josh Gorges.
Crosby lost out on another assist 1:04 into the second after a goal awarded to Chris Kunitz was reversed by a video review, the first of two tallies denied to the Penguins forward during the game.
Crosby's contribution to Dupuis' goal late in the second didn't appear on the score sheet. The Penguins' captain was parked in front of Price when Dupuis drove a slap shot home for his sixth goal at 16:40.
Referee Mike Hasenfratz waved off a potential short-handed goal by Kunitz 3:57 into the third. Both Price and the puck ended up in the net after the Pittsburgh forward came into contact with the Canadiens goalie, who stopped Kunitz's shot on a breakaway.
"It was a great job by our team to stick with it," Kunitz said. "We were a little bit against the odds when a couple of replays went against us but it was great by Jordan to get that one to tie it up and then for Kris to come back in overtime and score a big goal for our team."
Moen brought the stunned Bell Centre crowd of 21,273 back to life moments after Malkin's goal when he fired a shot past Fleury into the top right corner from the left faceoff circle.
Pacioretty gave Montreal a 2-1 lead with his team-leading 10th goal at 7:37.
Cole made it 3-1 with his seventh goal with 8:51 left in the second.
Malkin has eight points over the course of a four-game streak, including three goals and five assists. ... Canadiens RW Andrei Kostitsyn returned after missing 10 games because of a lower-body injury.