BOSTON -- The Toronto Maple Leafs knew they had to play more aggressively after a weak performance in the opener.
They wasted little time doing it.
"It was two strong teams playing against each other," Leafs forward James van Riemsdyk said. "We had to work really hard to get some bounces and we got some bounces tonight."
In the Bruins' 4-1 win on Wednesday night, they outshot the Maple Leafs 40-20 and applied pressure that gave Toronto trouble clearing the puck out of its zone to start its offense.
But on Saturday night, Toronto had several 3-on-2 and 2-on-1 rushes.
The Maple Leafs also delivered 22 hits in the first period to just 10 for Boston.
"We didn't answer enough," Bruins defenseman Dennis Seidenberg said. "We were the ones in the first game that initiated and it was them this time and we just didn't respond the way we're supposed to."
Nathan Horton gave the Bruins a 1-0 lead at 1:56 of the second period, but Lupul scored at 5:18 on a power play and at 11:56 with the teams at even strength.
Game 3 of the best-of-seven playoff series is Monday night in Toronto.
The Bruins played without Andrew Ference, part of their second defensive pairing, after the NHL suspended him for one game for elbowing Mikhail Grabovski in the head in the first period of the opener.
"You miss a veteran like that, but that wasn't the reason we lost," Bruins coach Claude Julien said. "We lost as a team."
And they had lost five of their previous seven games.
"There was some doubt and tonight eliminated that doubt," Toronto coach Randy Carlyle said. "We can go out there and compete."
It just took one bad game for the Maple Leafs, who have 15 players on their roster who hadn't been in the playoffs before, to get a feel for how the intensity increases.
"I think it helped for some getting those jitters out in that first game," van Riemsdyk said. "We did a good job of executing some things a little bit better."
Lupul had scored 11 goals in 16 games in the regular season. He missed 32 -- two on a suspension, five with a concussion and 25 with a broken forearm caused by a hard shot from teammate Dion Phaneuf.
Horton gave the Bruins the lead with his second goal of the series when he dropped the puck in the left circle for a trailing Milan Lucic then kept skating to the net. James Reimer stopped Lucic's shot, but the puck went off Horton's right skate and into the net.
Reimer finished with 39 saves for the Leafs.
Lupul tied the game just two seconds before Zdeno Chara was to leave the penalty box after being called for tripping. Gardiner fired a wrist shot from the left point, Tuukka Rask made the save, and Lupul put the rebound in on a short forehand shot.
Less than seven minutes later, Lupul got the go-ahead goal after Matt Frattin carried the puck deep along the right side then passed it across the slot where Lupul tipped it into the open left side of the net.
"It's good for me to get into a rhythm," Lupul said. "No matter how we played in the first game, we were still down 1-0. We were able to refocus. It doesn't matter how you lose."
Then Kessel, who led the Maple Leafs with 20 goals and 52 points, connected against the team he's struggled against since it traded him to Toronto in September 2009.
He began the night with just three goals and six assists in 23 games against Boston. And he got his usual round of jeers from Bruins fans nearly every time he was on the ice.
But he provided a two-goal cushion when he raced behind Boston's defensemen, took a pass from Nazem Kadri past the red line and fired the puck between Rask's pads.
"It's not easy for him here. They boo him a lot," Lupul said. "He's battling hard and they're putting a lot of attention on Phil. It's great to see him get one."
And now the Maple Leafs will be playing in the first playoff game in Toronto in nine years.
"We're looking forward to going back home and having playoff hockey in Canada," Lupul said. "We know it's been a while."
Jeff Bauman, who lost both legs in the Boston Marathon bombings, went on the ice in a wheelchair before the game. He smiled, pumped his fist and waved a big Bruins flag while wearing the team's jersey. He had been photographed being taken to emergency medical treatment minutes after the explosions by Carlos Arredondo, who was wearing a cowboy hat, and others. ... Boston's Brad Marchand limped to the bench with about five minutes left in the second period and went out the runway toward his locker room. But he was back on the ice soon after. ... Toronto nearly scored 90 seconds before Lupul's second goal when Nikolai Kulemin's shot clanged off the post.