MONTREAL -- The Golden Knights are back on level terms in the Stanley Cup semifinals.

Nicolas Roy scored his fourth goal of the playoffs at 1:18 of overtime as Vegas defeated the Montreal Canadiens 2-1 on Sunday to even the teams' third-round series 2-2.

The Quebec-born centre fired home on a scramble after former Montreal captain Max Pacioretty took the initial shot on Carey Price.

Robin Lehner -- starting in place of Marc-Andre Fleury after his disastrous miscue gifted the Canadiens a late equalizer in Friday's 3-2 OT loss -- stopped 27 shots for the Golden Knights. Brayden McNabb had the other goal.

The best-of-seven series returns to Vegas for Tuesday's Game 5.

Game 6 goes Thursday back in Montreal, while Game 7, if necessary, will be played Saturday in Sin City.

Paul Byron replied for the Canadiens, who got 19 saves from Price.

The winner of Montreal-Vegas will meet either the Tampa Bay Lightning or the New York Islanders in the Cup final. That series sits tied 2-2.

With the score tied 0-0 late in the second period and Montreal having just killed off the game's first power play, Byron took a pass from Nick Suzuki and moved in alone on Lehner and roofed his third of the post-season with 65 seconds left on the clock to send the 3,500 fans at the Bell Centre into a frenzy.

There wasn't much happening prior to that effort from Byron, who was on waivers three times during the regular season, as the crowd and both teams got increasingly frustrated with the officiating in a chippy affair.

Pacioretty forced a big save out of Price on that power play before Alex Pietrangelo, looking for his fourth goal in three games, rang a shot off the post.

Suzuki then exited the box and fed Byron for Montreal's breakthrough.

Lehner kept his team in the fight midway through the third by stopping Montreal rookie sniper Cole Caufield on a breakaway with the Bell Centre again poised to explode.

Vegas got its sixth goal from a defenceman in the series -- the Golden Knights have seven in total -- to tie it at 10:37 when McNabb pinched down and took a pass from William Karlsson before firing a shot that somehow squeezed past Price to force OT for the second time in as many games.

Montreal dropped its first overtime game of the playoffs (4-1) while the Golden Knights won their first (1-3).

The Canadiens were once again without interim head coach Dominique Ducharme after he tested positive for COVID-19 on Friday. Luke Richardson, who picked up his first NHL victory in Game 3, was again calling the shots behind Montreal's bench with the support of fellow assistants Alexandre Burrows and Sean Burke.

The Golden Knights also have a COVID-19 issue of their own after it was revealed a few hours before Game 4 that general manager Kelly McCrimmon was placed in self-isolation following a positive test.

Fleury had started 15 of 16 games in these playoffs for Vegas coming into Sunday -- Lehner got the call in a 7-1 drubbing by the Colorado Avalanche to open the second round -- putting up a .921 save percentage and a 1.97 goals-against average.

But the 36-year-old Vezina Trophy finalist turned the puck over behind his net with less than two minutes left in Friday's third period and his team cruising to a 2-1 series lead to Josh Anderson, who promptly scored into the unguarded cage to force OT.

Anderson then won it in the extra period on a 2-on-0 rush off a Byron feed with Vegas caught on a bad change.

Vegas, which finished second in the regular-season standings, 23 points ahead of 18th-ranked Montreal, dominated the opening 40 minutes of Game 3, outshooting the Canadiens 30-8, before the wheels fell off following Fleury's gaffe.

Thoroughly dominated in Friday's opening period, the Canadiens matched their excellent starts in the first two games of the series early Sunday, forcing Lehner into a couple terrific saves.

Montreal winger Corey Perry -- sporting a stitched-up gash on his face after taking an uncalled overtime high stick 48 hours earlier -- slid a pass across to Eric Staal as he was being hauled down, but Lehner stretched to make a left-pad stop before denying Joel Armia with his glove on the goal line.

The series is the first cross-border matchup in the NHL this season, made possible by a federal exemption allowing teams to bypass Canada's 14-day quarantine requirements.

This report by The Canadian Press was first published June 20, 2021.