Call these Bruins whatever you want. Just don't call them rattled.

It's a mindset they don't acquire after allowing a goal. Look no further than their penalty-killing unit on Thursday night.

Ottawa's second-period power-play goal snapped Boston's streak of successful penalty kills at 27. It wasn't a pretty goal, but it came when the Bruins aren't used to seeing them: when they're down a man.

And on a night in which the Bruins just didn't have their "A-game," they found a way to put that goal past them and bounce back with an even more crucial penalty at the end of the third period which carried into overtime.

"Our [penalty kill] came up big at the end of the third and the beginning of overtime," said Bruins coach Claude Julien after Boston's 2-1 overtime win over the Senators. "I don't think we're getting rattled by getting scored on every once in a while. And it's nice to see the guys bounce back."

Milan Lucic received a two-minute penalty for "closing hand on puck" behind the Senators' net. The Bruins killed off 32 seconds of that power play in regulation while it was 5-on-4. But they then were forced to try and kill off 1:28 of that penalty with a 4-on-3 disadvantage in overtime.

"It's tough. You just try to work on the system that's put in place when you're killing," said Bruins forward Chris Kelly, who was out there for the successful kill in overtime. "Know who their threats are, try to anticipate where that puck's going, and try to get it down as much as possible."