Kit Rosmus scored twice, including the winner in overtime, to lead Portland/Deering to a 4-3 win over previously undefeated Cheverus/Kennebunk in the girls’ hockey City Cup on Monday at Troubh Ice Arena.

The winning goal came 33 seconds into overtime.

“Right off the faceoff, getting (the puck), I just took it around and made it work,” said Rosmus.

Rosmus also tied the game at 3-3 in the third period, capping a 28-second flurry in which three goals were scored.

Despite the loss, Cheverus (7-1) is still ranked No. 1 in the South region. Portland (7-3) is ranked second.

“For the program, (this win is) off the charts,” said Portland Coach Tom Clifford. “The older kids have talked about never beating Cheverus.”

“Cheverus is a good team, they always have been,” said Rosmus. “Being able to tie it up that late in the game and then come back and win it. That’s everything.”

Portland entered the third period trailing 2-1. The Bulldogs tied it 54 seconds into the third on a slick wraparound goal by Emily Demers.

Just 9 seconds later, Caitlin Wolff put Cheverus back in front with a wrist shot to the near side of goalie Caroline Lerch. But Rosmus answered 19 seconds later.

“Tonight was our final step in learning how to win against a really, really good team,” said Clifford.

There were six penalties in the third period – five against Cheverus, including a double minor that resulted in a five-on-three power play.

“How do you generate offense when you’re constantly killing penalties? For a matchup of the two top teams in the conference, those were tough penalties to swallow,” said Cheverus Coach Scott Rousseau.

Cheverus was able to kill off every Portland power play.

“The girls showed a lot of character and composure. They showed a lot of heart, fought hard. It’s all right, that’s hockey,” said Rousseau.

Cheverus took the lead less than three minutes into the game. After a faceoff win, Sarah Noyes fired a shot between Lerch’s pads for a power-play goal. Zoe Mazur was credited with an assist.

Portland answered 51 seconds later when forward Margaret Smith scored with an assist from Inez Braceras.

The Stags regained the lead late in the first, thanks to an impressive goal from freshman center Emma McCauley. McCauley gained control of the puck in the defensive zone, quickly created a one-on-one situation with a Portland defender, then made a deke and slipped the puck past Lerch’s right pad.

Lerch is usually a first-line winger, but Clifford wanted to surprise Cheverus with an unfamiliar face in net.

“It was a really hard decision not to play our senior goalie. We just kind of felt we had to throw something at Cheverus that would make them really start thinking,” said Clifford.

Lerch finished with 17 saves.

“I knew that I could hold my own and stay in there,” said Lerch.