BOSTON -- All the Bruins really needed was one more offensive line to show up.

While much of the talk will be about the absence of Zdeno Chara for most of the third period on Sunday night against the Montreal Canadiens, the Bruins' real problem was that they had only one of their four offensive lines clicking.

Chara was in the penalty box for both Montreal goals in the third period. He was sticking up for one of the Bruins' top offensive players in Tyler Seguin.

The B's can't afford to lose Seguin, so when Alexei Emelin put a cross check into Seguin's ribs late in the second period, Chara went after the Canadiens' defenseman.

Chara's absence is never a good thing. But down one goal, as a third-period team, perhaps all the Bruins really needed was another line to step up. Because by the time the third period began, Patrice Bergeron, Brad Marchand, and Seguin had carried the load and helped Boston to a 3-2 lead after two periods.

"By far, they were our best line tonight," said Bruins coach Claude Julien after their 4-3 loss to the Canadiens. "And that's the unfortunate thing. We didn't have enough of our other lines going for us. And you can't win big games like that, relying on just that one line. We need more out of the other lines. And tonight wasn't a night where we got that."

Seguin scored his fifth goal of the year and tied the game at 1-1 midway through the first period, after Bergeron fed him a pass through the slot. The play got started because Marchand won a race to the puck down below the left circle.

Bergeron scored Boston's second goal to tie the game at 2-2, after he received a pass across the top of the crease from Seguin, after Seguin took the puck down the left wing and toe dragged around a sliding Emelin in front of the Montreal net.

The Bruins then took a 3-2 lead after Dougie Hamilton stood at the bottom of the left circle and one-timed a cross-ice pass from Marchand.

Bergeron, Marchand, and Seguin were the only three Bruins forwards to finish Sunday's loss with a positive plus/minus. Bergeron and Marchand finished at plus-3, while Seguin was plus-2.

"We've been clicking pretty well this year," said Marchand. "But I think tonight was another example that we had a lot of really good opportunities. Another one there at the end. It would have been nice if a few more found the net, but that's how it goes."

"I thought we were playing real well," said Bergeron. "We were clicking most of the night, well, pretty much all night. I felt pretty good. I thought we were moving our feet real well. But also, we were first on loose pucks. And we had some really good looks."

They were the only Bruins line that did all night. And as Julien pointed out after the loss, perhaps they just needed one more line to make a difference.

"I think Patrice had a great night," said Julien. "Obviously [Marchand] with the three assists. And Tyler, I thought, was skating well and competing well. It was a good line for us. Another line or two like that, with that same work ethic, and we would have been fine."