Krejci beat James Reimer with a shot from the faceoff circle after coming down the left wing.
The Bruins mobbed David Krejci after his third goal of the game sent goalie James Reimer and the Maple Leafs home with a 3-1 series deficit.
The Bruins are 15-2 when leading a best-of-seven series 3-1. And Toronto is 2-12-1 in its last 15 games in Boston.
The Bruins have not lost a playoff game in Toronto since 1959.
The Leafs used their speed to great effect and led 2-0 after the first period, only to see the Bruins fight back to take a 3-2 lead in the second. Toronto stopped the slide with a late goal of its own.
Tied 3-3, it was desperate high-stakes hockey, with players putting their bodies on the line. Toronto defenseman Mark Fraser, who does not wear a visor, took Lucic’s shot in the face with 12 minutes remaining and headed to the dressing room, leaving a pool of blood on the ice.
The overtime was even more tense.
Inside the Air Canada Centre, the chant of “Go Leafs Go” started before the anthems. Outside, blue-and-white fans came out early to party in the adjacent Maple Leaf Square.
Lupul gave them something to cheer about on the Leafs’ first shot. Lupul gave the puck to Phil Kessel who raced around the goal and then fed it back to Lupul. He had enough separation from the Boston defensemen to slap the puck past Rask for his third of the playoffs.
Reimer had stopped Jaromir Jagr with a pad save and then handled the shot from the ensuing rebound seconds earlier.
Krejci had a glorious chance to tie it late in the period but rattled the puck off the post with the goal wide open. That hurt Boston when Franson doubled the lead with a shot from the point that beat Rask, who had Chara in front of him, with 1:28 to go in the period.
There were seemingly ominous signs for Boston, which trailed after 20 minutes for the first time in the series. Chara was on the ice for both goals in the period.
But the Bruins showed their character in the second period, pushing back on the power play just 32 seconds in. An opportunistic Bergeron beat Reimer on a rebound of a screened shot from the point by Chara. It was Bergeron’s first point of the series and first goal in 14 games.
Chara also began to assert himself, laying out Leafs and using his wingspan to defend the puck.
Krejci was credited with Boston’s second goal after a goalmouth scramble that saw Mikhail Grabovski go flying. Chara had helped set the stage with a driving rush.
The Boston power play, which was 1 for 9 coming into the game, paid off again with Krejci one-timing a shot past Reimer after a pass from Horton.
MacArthur, who replaced Ryan Hamilton in the lineup, tied it 44 seconds later with a slap shot from the slot.
Boston finished the period killing off a 5-on-3 disadvantage.
Lucic was cut in the face by a shot from Chara as the first period ended. He was hunched over as he skated off before a trainer gave him a towel to stem the flow of blood. … Jaromir Jagr picked up an assist, giving him sole possession of sixth place on the all-time playoff points list (191). … Toronto went 0 for 4 on power plays.