Adam McQuaid, Rich Peverley, Nathan Horton, Daniel Paille and David Krejci, with an empty-net goal with 1:17 remaining, scored for Boston, a playoff-savvy squad that came out with an edge. And left with an edge in the series 2-1.
``I think, as a team, we played a good road game,'' Krejci said. ``Maybe we didn't have as many chances in Game 1 (a 4-1 Boston win), but I think it was a perfect road game and I'm pretty happy about that.''
Game 4 is Wednesday night.
The loss came before 19,746 amped-up fans inside the Air Canada Centre. Outside, a blue-and-white throng watched on a big screen in Maple Leaf Square as playoff hockey returned to Toronto for the first time since 2004.
``The crowd was awesome,'' said Leafs forward James van Riemsdyk. ``One of the loudest I think I've played in front of in the NHL.''
Didn't make much difference in the end. Toronto's errors did.
``They made less mistakes than we did and their execution level was above ours,'' Toronto coach Randy Carlyle said.
``Mistakes just killed us tonight,'' echoed defenseman Jake Gardiner, who scored his first playoff goal.
The dominant line of Milan Lucic, Krejci and Horton finished with two goals and six assists. They have combined for 17 points through the first three postseason games, with five goals and 12 assists.
Veteran Jaromir Jagr also showed off his skills, setting up a goal and controlling the puck as if it was glued to his stick.
``Vintage Jagr in the offensive zone,'' Boston coach Claude Julien said of the longtime NHL star.
Phil Kessel accounted for the other Toronto goal in a physical game.
The Leafs charged hard in the third period, outshooting Boston 18-6 for a 47-38 overall edge. But Tuukka Rask stood tall in the Boston goal.
``They came out in the third a desperate team,'' said Julien.
It was the first Leafs' home playoff game since May 4, 2004, when Toronto lost 3-2 in overtime to Philadelphia to lose the conference semifinals 4-2. Fans were rewarded for patience with free scarves, but not with a win.
The last home playoff win came in that same series, a 3-1 victory on April 30, 2004.
For the Bruins, the playoffs are business as usual. Boston, which won the Stanley Cup two years ago, is in the postseason for the sixth straight year.
The Leafs were punished for their mistakes, losing while getting their most shots since they managed 43 in a January loss to the New York Islanders.
``We hung him out to dry a couple too many times,'' van Riemsdyk said of Leafs goalie James Reimer, who deserved better. ``That was the difference in the game.''
Inside the arena, chants of ``Go Leafs Go'' started before warm-ups. Even the national anthem singer got an ovation, with the crowd belting out ``O Canada'' with him.
The crowd showed Kessel some love, chanting ``Thank You Kessel.'' That was unlike in Boston, where fans used the chant to taunt the former Bruin.
Toronto outshot Boston early but it was Reimer called on to make a huge save midway through the period. He gave up a rebound and Tyler Seguin swooped in, but Reimer stopped his close-range backhand with his blocker.
The Bruins had an edge about them and scored first when McQuaid's shot from the point beat Reimer to the stick side. The Toronto goalie looked aghast, as if the puck had done something strange before passing him.
It was Boston's seventh goal of the series and the fourth scored by defensemen.
Boston went ahead 2-0 when 41-year-old Jaromir Jagr, who was lively all night, stripped Ryan O'Byrne of the puck behind the goal and fed Peverley, who stuffed it past a helpless Reimer.
Dion Phaneuf hit the Boston goalpost after skating in from the point and taking a perfect pass from Nikolai Kulemin. Then Gardiner got the fans out of their seats when Bruin penalty killer Chris Kelly's failed clearance went to him. Gardiner skated in from the blue-line and snapped a shot over the glove of Rask for his first playoff goal.
The fans were still celebrating - inside and outside the building - when Lucic cruised down the left wing and sent a laser-like pass to Horton, who beat Reimer.
The Bruins' onslaught continued as Kessel gave up the puck on a power play and Paille raced in alone to beat Reimer with a backhand.
An opportunistic Kessel closed the gap to 4-2 just 47 seconds into the third period. Rask slid out of position and Kessel fired it into the net over a sliding Bruin.
That earned another round of ``Thank You Kessel'' chants. There wouldn't be enough of them for the Leafs, though.
NOTES: Jagr's assist on Boston's second goal was his 190th career NHL playoff point. That tied him with Brett Hull for sixth place on the league's all-time playoff points list. ... The last home playoff win for Toronto came in that same series with the Flyers, a 3-1 victory on April 30, 2004. ... It was the most shots allowed by the Bruins in a playoff game since Montreal's 51 in a double-overtime game on April 23, 2011. And it was the most shots allowed by the Bruins in a non-overtime playoff game since April 11, 1975, when Chicago had 56 in a 6-4 Blackhawks win.