TORONTO (AP) Morgan Rielly's second goal of the game, on a deflection of Mitch Marner's shot, at 3:54 of overtime gave the Toronto Maple Leafs a 4-3 win over the Boston Bruins on Saturday night.
Alexander Kerfoot and Dmytro Timashov also scored in regulation for the Maple Leafs, and Marner had two assists. Frederik Andersen stopped 42 shots.
David Pastrnak had a goal and an assist, and Jake DeBrusk and Danton Heinen also scored for the Bruins. Jaroslav Halak finished with 25 saves.
Rielly's winner came after Marner took a feed from Auston Matthews and ripped a shot that deflected off Rielly's shin past Halak's blocker with the teams playing 3-on-3 in the extra period.
Down 2-1 despite a dominating second, the Bruins tied the score at 1:36 of the third just as a Leafs' penalty was about to expire when Heinen wired his first upstairs on Andersen.
Toronto replied just 61 seconds later when Kerfoot backhanded a loose puck past Halak for his third of the season.
Andersen faced 33 shots through two periods, and the Boston kept coming late in the third, with Pastrnak tying things with 4:26 left in regulation when he blasted a one-timer for his ninth.
Pastrnak now has nine goals on the season, including seven in the last three games, which puts him in a tie with Edmonton's James Neal for the NHL lead.
The Maple Leafs played their first game without captain and star center John Tavares, who broke a finger Wednesday and will miss at least two weeks. The Bruins, meanwhile, were minus veteran center David Krejci (upper-body injury) for a third straight game.
Toronto has lost to Boston to open the playoffs each of the last two years - with both series going to a Game 7 - but with Tavares, Zach Hyman (knee) and Travis Dermott (shoulder) all out injured, and some major roster restructuring in the off-season, just nine of the 18 skaters who dressed for the Maple Leafs in the deciding game back on April 23 were in Saturday's lineup.
The Bruins, who went onto make the Stanley Cup Final before losing on home ice in Game 7 against the St. Louis Blues, dressed 13 skaters from that 5-1 victory against Toronto.
The Maple Leafs opened the scoring at 5:55 of a spirited first period when Rielly's point shot with Johnsson battling in front went in off Bruins defenseman Brandon Carlo and in for his first of the season.
DeBrusk came close to tying the game a few minutes later when he blew past Tyson Barrie, but Andersen made a nice toe save.
Timashov made it 2-0 on a good fourth-line shift from Toronto. The rookie forward got the puck from Frederik Gauthier and moved into the slot before roofing his first NHL goal past Halak.
The Bruins, who had 18 shots in the first, finally got on the board with 20.6 seconds left in the period when DeBrusk took advantage of some poor defending to beat Andersen from in-close.
Coming off Thursday's 4-3 shootout loss at home to Tampa Bay, Boston fed off that goal in the second and had Toronto on its heels for long stretches.
The Maple Leafs' best chance of the second came after Sean Kuraly threw the puck in front of his own net, but Barrie was robbed by Halak with the glove.
NOTES: Halak, who has shared the Boston crease with Tuukka Rask to start the season, made his fourth start. ... U.S. Open and Rogers Cup champion Bianca Andreescu of Mississauga, Ontario, dropped the puck for the ceremonial faceoff. ... Attendance was 19,394. ... Maple Leafs coach Mike Babcock threw an early curveball with Tavares out after going through Friday's practice and Saturday's warmup with Matthews centering William Nylander and Andreas Johnsson, and Alexander Kerfoot between Marner and Ilya Mikheyev. Babcock instead started with Matthews-Marner-Johnsson and Kerfoot-Nylander-Mikheyev, and tinkered with his top-6 at times throughout the night.
Bruins: Host Toronto on Tuesday night.
Maple Leafs: Host Columbus on Monday night.
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