The Maine men’s hockey team treated a large Portland crowd to one frenetically beautiful period of hockey Saturday.

And then watched New Hampshire steal the momentum and the game. The Black Bears allowed the Wildcats to walk out of the Cross Insurance Arena with a 7-4 victory and a split of their weekend series.

Maine (4-13-1) was sluggish at the outset, falling behind 2-0 after one period. In the second, they roared back with 16 shots on New Hampshire freshman goaltender Adam Clark, breaking through for four goals and even breaking Clark’s finger on one sequence. Blaine Byron scored Maine’s first goal on that play and added its final goal with 0.1 second remaining in the period to build an improbable 4-3 lead and delight the announced crowd of 6,183.

Inexplicably, it was sluggish Maine that returned to the ice for the third period, wasting all that energy.

“The thing that infuriated me more than the third period was how we played the first,” Maine Coach Red Gendron said. “You can say, ‘Yeah, it’s great they came back.’ But that’s not the way to be successful as a hockey team, to play a period and maybe half of another one and to flat-out refuse to do the things that you know work. That’s a problem.”

The Wildcats (5-10-1), meanwhile, followed the gritty lead of Clark, who stayed in the game after being bowled over prior to Byron’s goal 57 seconds into the second period. He was attended to by doctors while the score was reviewed.

Clark (33 saves) has played all but 6 minutes for New Hampshire this season and his usual backup, Jamie Regan, didn’t dress Saturday due to illness. That meant Greely High School graduate Matt Labbe, a senior who has never appeared in a collegiate game, would have been the next man in.

“Adam Clark was tremendous. I thought we were going to have to take him out of the game in the second period,” New Hampshire Coach Dick Umile said. “It was a gutsy game for him and the team responded.”

New Hampshire had surrendered five unanswered goals in a 5-2 loss to Maine on Friday. The Wildcats hadn’t scored more than two goals in any of their past six games, all losses.

Maine was on a path to continue those trends. Byron got his second goal of the game and team-leading eighth of the season just as the horn sounded to end the second period. Dan Renouf fed Ben Hutton, who emerged from the penalty box with 8 seconds remaining and a clear path to Clark.

“The goalie made a really nice toe save on him and I was able to follow up the play, and he was able to get it to me and just fortunate enough to beat the clock. I had no idea how close it was,” Byron said.

The goal was upheld by review, sending Umile storming to the locker room berating the officials.

Just 31 seconds into the third period, Maine’s Devin Shore was called for tripping and that opened the door for the Wildcats, who got a power-play goal from Downing Grayson to tie the score 20 seconds later. The Black Bears never recovered, Grayson scored twice more in the period and Cleland Matias netted the winner at 11:59.

“We were carrying the game. I don’t know if we got too relaxed going into the third or if something switched on with them and we just didn’t get back to our game,” Byron said.

“It’s hard when the team scores right off the bat like that. But to be a good team, you have to find a way to dig past that. I don’t think it should bug us.”

But it did. And it especially bugged Gendron, who was at a loss to explain how his team folded just when it seemed to find some fortune.

“The bench was dead in the first period. It was like, ‘Oh, jeez, we’ve got to play a hockey game,'” Gendron said.

“You’ve got to ask (the players). I don’t understand.”