ROCHESTER, N.H. — Keith St. Cyr didn’t try to downplay the significance of what happened late in the third period Tuesday night.

His Noble/Wells hockey team rallied with two power-play goals, by Ryan Marsh and Chullainn Kelly, 45 seconds apart to upset Cheverus 4-3 in the Western Class A quarterfinals at the Rochester Ice Arena. All four of the Knights’ goals came on the power play.

Yes, the Knights entered the game seeded higher (fourth) and with a better record. But even they knew this was an upset.

“It’s historic, honestly,’’ St. Cyr said of the win. “This is really a tribute to all the kids who played in this program for 11 years, playing to get to this point. This is the furthest we’ve ever gone. It’s not only a big reward for the guys here but to all those who made this program what it is.’’

The Knights (15-4) will play Falmouth at 8:45 p.m. Saturday in the regional semifinals at the Androscoggin Bank Colisee in Lewiston.

Cheverus, seeded fifth, finished 9-9-1.

Noble junior Dean Pratt had two assists, his first giving him 100 points in his high school career.

The Stags dominated the third period, at one point outshooting Noble/Wells 12-2, as their depth and three lines were wearing down the Knights and their two lines.

And Cheverus took a 3-2 lead on a textbook tip-in goal by Jesse Cyr-Brophy with 7:17 left in the game.

Stationed at the left post, he stuck his stick out and tipped the hard drive by Alexander Grant-Roy into the empty corner, past Knights goalie Wyatt Ricker.

But Cheverus took two penalties that cost it the game.

The first came with 4:54 left, and it took the Knights 13 seconds to tie the game.

Conner Pease, who scored Noble’s first goal, took a shot from the right circle that Jason Blier (29 saves) stopped. The rebound came into the slot, where Marsh controlled it and placed a backhander inside the left post with 4:41 left.

Then with 4:05 remaining, the Stags took another penalty. This time it took nine seconds for Noble/Wells to score.

The draw came to Pease, who passed to Kelly at the left point. His shot through a screen found the top far corner and the Knights suddenly led 4-3 with 3:56 left.

“We were running our power play,’’ said Kelly. “I just saw an opening to his glove side. I just took a shot, and hoped for a tip, hoped for the best.

“And I got it.’’

St. Cyr shook his head when it was mentioned that all four Noble/Wells goals came on the power play.

“It was the worst part of our game all season,’’ he said. “For it to work here, I guess that shows all the work that was put into practice the last month really paid off.’’

Ricker (25 saves) secured the victory when he made a stop on Cheverus’ James Hannigan after he split two defenders and got in close.

Cheverus Coach Dan Lucas said the Stags couldn’t keep their late-season momentum going.

“I thought our schedule was the toughest one we’ve played since I’ve been here, which is what I wanted,’’ he said. “I thought it would help us. But we didn’t win the one we needed to win to keep going. They did.’’

And the Knights were savoring it.

“This is huge,’’ said Kelly. “It’s our first home playoff win. We wanted to win.

“We were never thought of as a team that could make it, get into the playoffs. We finished fourth and we proved we belonged here and it wasn’t just a fluke.’’

Mike Lowe can be reached at 791-6422 or at:

mlowe@pressherald.com

Twitter: MikeLowePPH