Boston College goaltender Matti Kaltiainen waited all night to make a big save. With just seconds remaining in regulation, he got his chance.

After Merrimack tied the game with 34 seconds left, Kaltiainen (13 saves) stopped Marco Rosa with 15 seconds to play on a partial breakaway, setting up Chris Collins’ breakaway goal at 1:35 of overtime as Boston College defeated Merrimack, 3-2, to claim sole possession of first place in Hockey East.

Throughout the night, Kaltiainen saw few quality shots. But in the closing minute, he stopped Rosa once before the puck reached Brian Schmidt at the top of the faceoff circle for the tying goal, and then the aforementioned save on Rosa to send the game to OT.

“I got a piece of it with my pad,” said Finnish-born Kaltiainen of the save on Rosa. The play began as a three-on-two before Rosa was isolated down the left side, cut to the net and appeared to have the Eagle ‘tender beat. But as Rosa shot, Kaltiainen’s final stretch of the leg seemed to deflect the puck to the corner.

“We wanted to win the game [in regulation],” admitted Eagle head coach Jerry York. “We got three guys caught at the goal line and they broke on a clean three-on-two.

“It looked like [Kaltiainen] just got his skate on it on a bang-bang play.”

Once the Eagles caught their breath and made it to the overtime, the freshman duo of defenseman Peter Harrold and Collins connected for the game winner.

Quickly transitioning off of a defensive zone draw, Harrold sent an 80-foot pass to a streaking Collins that found him in stride two feet short of the blue line. From there, he was in clean on Merrimack goaltender Joe Exter and wristed a low shot five-hole for the winning goal.

“The two freshmen made a great play there,” said York. “Exter’s not an easy goalie to beat so you have to give Chris Collins credit on that one.”

Collins admitted he was surprised to get behind the defense in overtime but said that he saw the Merrimack weak-side defenseman break forward and he seized the opportunity to cut to the middle.

“It couldn’t have been a better pass,” said Collins, who now has nine goals and 20 points in his rookie campaign. “We’ve been told to keep it low and put [the puck] by [Exter’s] feet. I saw him come out and did that to put it by him.”

Friday’s game began a half-hour late as Merrimack had bus trouble on the way to Chestnut Hill. Once the game did begin, it looked as if the Warriors never left the broken bus, as the Eagles dominated every facet of the game, to the chagrin of Merrimack coach Chris Serino.

“I thought we played awful for two periods,” said Serino. “Joe [Exter] kept us in and we were able to tie it up. But it’s inexcusable to give up a breakaway in overtime.”

In the opening frame, BC outshot Merrimack, 12-4, with grade-A opportunities favoring the Eagles, 8-0. Still, thanks to the play of Exter (32 saves), the Eagles held only a 1-0 lead at intermission.

The Eagles’ goal came at 8:05 when Merrimack defenseman Nick Cammarata lost his man, David Spina, in front. Collins fed a quick pass to Spina that allowed him to deke Exter and roof a shot for the 1-0 lead.

Despite dominating the first half of the game, the Eagles found themselves tied at one as Merrimack sophomore Brendon Clark was the beneficiary of puck luck to even the score. Clark’s centering pass hit Eagle defenseman Brett Peterson, bounced in the air where all of BC lost track of it and landed just inches from the near post. All Clark had to do was tap the puck in for the goal.

As Merrimack began to turn on the pressure through the middle of the period, momentum was taken away when Tony Johnson was whistled for high sticking at 13:52. On the ensuing power play the dangerous Andrew Alberts was left open for a one-time blast from the point. Though Exter made the original save, the shot opened Spina at the left post for him to wrist in his second of the game, giving BC a 2-1 lead through two.

With Merrimack more alert defensively in the third period, the Warriors clogged up the neutral zone and limited the Eagles’ chances. All of that built up to the opportunity to pull Exter for the extra attacker, and Schmidt to even the score at 19:26.

After Kaltiainen’s save on Rosa, the puck bounced off numerous skates and Schmidt simply floated a backhanded from 50 feet over the left shoulder of the Eagle ‘tender to shock the 4,808 in attendance.

“I never saw the shot,” said Kaltiainen of the tying goal. “I knew the puck was somewhere in front and then it came out of nowhere and went in.”

But the Eagles’ netminder, who improved to 13-6-2 on the season, saw the most critical shot when he stopped Rosa in the waning seconds of regulation to send the Eagles to OT and victory and the home crowd into jubilation.

Coupled with a 5-1 loss for Maine to Providence on Friday, BC’s win leaves it alone in first place in Hockey East with five games to play. Maine and New Hampshire each sit two points behind.