Bottom-seeds Chicago, Montreal and Arizona completed shocking upsets in the qualifying round Friday to reach the Stanley Cup playoffs, the worst teams inside the National Hockey League bubbles eliminating favourites.
Chicago's Dominik Kubalik scored the game-winning goal 8:30 into the third period to give the 12th-seeded Blackhawks a 3-2 upset over Western Conference bubble host Edmonton, a fifth seed, and a 3-1 victory in their best-of-five play-in series.
The other rink stunners saw East 12th seed Montreal down Pittsburgh 2-0 to claim that series 3-1 and West 11th seed Arizona edge Nashville 4-3 in overtime, the Coyotes winning their first post-season series since 2012 in four games.
The NHL return from a March 12 COVID-19 shutdown saw 12 teams each enter quarantine bubbles in Toronto for the East and Edmonton for the West -- four top teams from earlier games deciding playoff seedings and eight others playing a qualifying round for playoff spots.
Jonathan Toews cleared the puck from behind the goal to set up Kubalik's decisive slap shot and the Hawks booked a date against the West top seed in the first best-of-seven round of the playoffs, which open Tuesday.
Colorado and the Vegas Golden Knights meet Saturday with the winner taking the West top seed.
Montreal's Artturi Lehkonen opened the scoring with 4:11 remaining in the third period and the Canadiens, who had the worst record of the 24 returning NHL teams, spoiled the 33rd birthday of Penguins captain Sidney Crosby, a three-time NHL champion and two-time Olympic gold medalist.
"It was an important goal for sure," Lehkonen said. "We showed up to the camp ready to play and knew we would have a chance. Now we've just got to move on to the next one."
Carey Price made 22 saves for Montreal for his sixth post-season shutout, his first since 2015, the last year the Canadiens had won a post-season series.
Shea Weber scored an empty-net goal with 32 seconds to create the final victory margin for Montreal, which faces a first-round playoff series against the East top seed, the winner of Saturday's game between Tampa Bay and Philadelphia.
Brad Richardson scored on a backhand shot 5:27 into overtime to give the Coytotes their first playoff berth in eight years.
"It hit off my shin pad and kind of hung around," said Richardson, who was camped out on the edge of the goal crease. "Luckily I got the rebound and put it in."
The Coyotes, who moved from Winnipeg to Arizona in 1996, won their only prior post-season matchups in 2012 and hadn't reached the playoffs since.
"It means a lot," Richardson said of ending the drought. "It just feels like a lot of hard work came to fruition. We have a long way to go, but that's a big hurdle for our team and it feels really good.
"We've had a lot of adversity. We tried to put it in the back of our thoughts and keep playing. I think we did that and we had a great win."
Nashville's Filip Forsberg scored with 31.9 seconds remaining in the third period to pull the Predators level and force overtime, but Arizona advanced to face the West second seed.
Anthony Beauvillier scored two goals and Semyon Varlamov made 24 saves to spark the New York Islanders over Florida 5-1 to complete a 3-1 victory in their East qualifying series.
The Islanders, rated seventh, will learn their next opponent after Sunday's final seeding games.