Cheverus made the big plays on both offense and defense to earn a 31-21 win over Portland in a Class A North football game Friday afternoon at Boulos Stadium.

The Stags’ defense got a touchdown and a safety in the first quarter, and the offense churned out 365 yards.

“It’s been a rough season up to now,” said Nathan Dunn, a senior linebacker who scored the game’s first touchdown two minutes into the first quarter when he pounced on a fumble in the Portland end zone.

“We hadn’t played four quarters of football. This was our best game. This was our best performance yet. We have some things we have to improve upon, but we’re definitely on the rise.”

Cheverus (2-3) opened a 16-0 lead in the first quarter.

The defense made it 9-0 when Sean Sullivan, a sophomore lineman, tackled quarterback Sam Knop in the end zone for a safety, after a bad snap.

Less than a minute later, fullback Teigan Lindstedt scored on a 2-yard run. The touchdown was set up by Sean Tompkins’s 32-yard return on the free kick after the safety, followed by Perrin Conant’s 35-yard pass to Vic Morrone.

“You try to make fewer mistakes than your opponents and take advantage when they make mistakes,” Cheverus Coach Mike Vance said. “My kids were able to do that today.”

Portland (0-5) rallied to make a game of it, however.

With less than two minutes left in the first half, Knop threw a 5-yard scoring pass to Vinnie Pasquali. The Bulldogs twice converted on fourth down to keep the 12-play, 54-yard march alive.

Portland seemed to grab the momentum when Pasquali returned the second-half kickoff 85 yards for a touchdown. It took him 20 seconds to complete the runback as he zigzagged down the field, coming to full stop three times to avoid potential tacklers. None of the defenders laid a hand on Pasquali.

Cheverus regained control, though, with a couple big plays.

With less than four minutes left in the third quarter, the Stags extended their lead to 23-14 when Max Coffin took a screen pass from Conant and ran 64 yards down the left sideline.

Portland was stopped on downs at the Cheverus 12 on its next possession. Then, on the final play of the third quarter, Tompkins ran 85 yards on an end-around to make it 31-14.

Portland cut the deficit to 31-21 with about eight minutes left when Knop threw a 30-yard scoring pass to Pasquali. The touchdown was set up by linebacker Nathan Kapongo’s fumble recovery at the Cheverus 32.

The Stags ran out the clock from there, though, holding on to the ball for the final 12 plays.

“We moved the ball up and down the field,” Portland Coach Jim Hartman said, “but a handful of plays here and handful of plays there made the difference.”

Coffin gained 90 yards on 22 carries, and Conant was 4 of 6 for 126 yards.