Brad Marchand scored the go-ahead goal and Tuukka Rask stopped 31 shots as the Boston Bruins rolled over the Toronto Maple Leafs 3-1 to seize a commanding 3-1 playoff series lead.

Jake DeBrusk and Torey Krug also scored in the win on Thursday night for the Bruins, who were missing star centre Patrice Bergeron with an undisclosed injury.

David Pastrnak tallied two assists in front of the crowd of 19,600 at the Air Canada Centre arena in Toronto.

“Early on, they were better,” said Bruins coach Bruce Cassidy. “Then we finally found our legs and started managing the puck better, got stronger, we came on and scored.”

Boston can wrap up the first round Eastern Conference series with a victory in Game 5 on Saturday at the Boston Garden.

Tomas Plekanec scored once and goaltender Frederik Andersen stopped 18 shots for Toronto, who were coming off a 4-2 win in game three at home.

Bergeron had been a key element on the top line that dominated in the first two games of the series which the Bruins won 5-1 and 7-3. But he was a surprise late scratch on Thursday and the Bruins declined to give details about the injury.

He was replaced on the top line between Marchand and Pastrnak by Riley Nash, who finished with one shot on goal in 19:10 minutes of playing time.

Krug silenced the Maple Leaf crowd with the opening goal just 28 seconds into the contest. His snapshot from the side boards deflected off Andersen’s shoulder into the net.

After Marchand scored in the second, Boston made it 3-1 at 4:17 of the third. DeBrusk finished off a two on one after taking a perfectly placed pass from David Krejci. Both Andersen, and the lone defenceman back, Roman Polak, looked helpless on the nice passing play.

“We gave them opportunities and they didn’t miss,” Leafs forward Mitch Marner said. “Now it’s do or die.”