With Andrew Ference out of the lineup due to a one-game suspension, the Bruins had to jumble up their defensive pairings prior to Game 2 of their first round series against the Toronto Maple Leafs Saturday night at the TD Garden.

Taking Ference’s place was Dougie Hamilton, who had a solid night in his playoff debut tallying four shots in his 13:32 of ice time. But with the reliable duo of Zdeno Chara and Dennis Seidenberg split for one game, the B’s lacked stability on the blue-line.

That was obvious as two second period tallies from Joffery Lupul and demoralizing goals from ex-Bruin Phil Kessel and James van Riemsdyk in the final stanza lifted the Leafs to a 4-2 victory.

“They put the pucks in the areas where they could put the pressure on us,” Seidenberg said about the Leafs. “They got us clean making the first pass and we kept turning the puck over and again we weren’t sharp enough to break it up.”

Throughout the night, the Leafs brought the intensity level. At times, the Bruins seemed to match it, but for the most part they were a step slower.

With their physical play and their speed, the Leafs took advantage of what was given to them and created several odd-man rushes thanks to their good forecheck. The Bruins, meanwhile, struggled to keep up on the backcheck.

“It wasn’t that bad. There were some times where we did a lot of good things, but it wasn’t the outcome that we wanted,” said Johnny Boychuk, who was paired with Seidenberg. “I think we just gave up too many odd man rushes and [we need to] tighten up a little bit.

“They just came out harder. They just played a lot harder and did a good job.”

In Game 1, the Bruins held the Leafs to 21 shots. But coming into Saturday, the B’s knew that the Leafs were desperate in their attempt to tie the series.

Despite being outshot 41-32, the Leafs’ transition game was much smoother and the Bruins defense had trouble handling the puck.

“We certainly weren’t as good and they were better. There’s no doubt there,” said head coach Claude Julien. “They played better than Game 1 and we didn’t play quite as well as we did in the first game. Certainly they made some adjustments and we were prepared for those kind of adjustments, but I think our execution wasn’t as good tonight.”

“I think the biggest difference was that they were managing the puck better than we were in the first game,” added Chara. “So we’ve got to get better and get ready for the next game.”

With Ference returning for Game 3, its safe to assume that Chara and Seidenberg will be paired again as they try to stop Kessel and company. But as the series shifts to Toronto, the Bruins won’t have the benefit of the last change like they did the last two games.

The defensive collapses were a sore spot for the Black and Gold for part of the season, but they’ll need to tighten up the blue-line. Otherwise the Leafs, who will play their first playoff game at the Air Canada Centre since 2004, will have a chance to dictate the tempo in front of their home crowd.

“We know it’s going to be noisy and there’s going to be a lot of electricity in the air. And we have to face that,” said Julien. “We’re the bad team coming in and what you’ve got to do is focus on your job and hopefully not let that kind of stuff throw you off your game.”