It was Lehner's first start in 21 days and his second in 42. He made 27 saves to help Vegas even the best-of-7 series.
Marc-Andre Fleury misplayed the puck behind the net in Game 3 on Friday, leading to the tying goal by Josh Anderson with 1:55 left in the third period. The Canadiens went on to win 3-2 in overtime.
Fleury, who was voted a finalist by NHL general managers for the Vezina Trophy, which is awarded to the best goalie in the regular season, started 15 of the Golden Knights' first 16 games in the Stanley Cup Playoffs. He is 9-6 with a 1.97 goals-against average, a .921 save percentage and one shutout. He has the best GAA of any goalie who has played at least 10 games.
Lehner, a finalist for the Vezina in 2018-19 with the New York Islanders, started Game 1 of the Stanley Cup Second Round against the Colorado Avalanche on May 30 and allowed seven goals on 37 shots in a 7-1 loss.
But he had not played since May 10, and the Golden Knights had one day to recover from a seven-game series against the Minnesota Wild while the Avalanche had six days to recover after sweeping the St. Louis Blues in the first round. Colorado had won nine straight games.
Lehner did not dress for Games 2 and 3 against Colorado for undisclosed reasons but backed up Fleury every game after that.
The Canadiens had won eight of their previous nine games entering Game 5.
Asked about rest versus rust in goalie decisions, Vegas coach Peter DeBoer said after the morning skate Sunday: "I think any players moving in, out of the lineup, that's always an issue. These guys practice every day. We've got a lot of veteran players. Any lineup decisions we make putting guys in, we throw all those factors into the hat when we're making those decisions."
DeBoer has said he will play the goalie who gives Vegas the best chance to win since the Golden Knights acquired Lehner in a three-team trade Feb. 24, 2020.
Lehner took the No. 1 job from Fleury in the playoffs last season. Fleury won the job back this season, when they shared the Jennings Trophy for helping the Golden Knights allow the fewest goals against in the NHL (122).
Lehner has supported his teammates from the bench in the playoffs, even tossing his hat on the ice to celebrate hat tricks.
"Robin's been doing everything to keep himself ready," defenseman Zach Whitecloud said. "He's a consummate pro and first and foremost a great teammate. He keeps himself ready, keeps himself dialed in, and he comes to the rink and has fun every day. So, he's one of the best guys to be around that I've ever been around."
Forward William Carrier said he felt Lehner would be ready if he got the start.
"We've got a great combination of two goalies," Carrier said. "They can play. Obviously, [Fleury has] been hot for us. So, whatever they do, I think the team's got 100-percent confidence in everyone in net."
