BRUNSWICK — In a goal-oriented sport, anything can happen. There is often a fine line between a win and a devastating loss.

Take the Class A North boys high school soccer quarterfinal Wednesday between fourth-ranked Brunswick and No. 5 Mt. Blue, for instance. In the first half, the host Dragons dominated possession and outshot the Cougars, 5-1.

But a pair of second-half tallies by Chris Marshall allowed Mt. Blue to advance with a 3-1 victory.

The Cougars (9-5-1) will next face top seed and defending Class A champion Lewiston on Friday in a regional semifinal. Brunswick finished 7-6-2.

“Taking nothing away from Mt. Blue, but this was a game that we certainly could have won, but when it came down to it, we didn’t execute and we had to press at the end,” said Brunswick coach Mark Roma.

Brunswick had several shots either sail high or wide into a strong, cool wind in the first 40 minutes. Mt. Blue goaltender Xander Gurney made five first-half saves.

At the other end, Mt. Blue took advantage of its lone opportunity. Standout Sam Smith was tripped up inside the penalty area and the Cougars were awarded a penalty kick. Mick Gurney buried the shot for a 1-0 edge.

“Brunswick was doing some great stuff, and they had a gameplan that worked for them in the second half of the season,” said Mt. Blue coach Joel Smith. “We knew at halftime one goal wasn’t going to be enough.”

It did not take long for Brunswick to find the equalizer in the second frame. Josh Musica gained control, took two strides and stepped into the ball, sending a low rocket just inside the left post for a 1-1 deadlock with 35:21 remaining.

“We talked about having to execute, and it was a lot of hard work,” said Roma, whose Dragons nearly gained a one-goal lead but Luke Cheseldine and Everett Horch just missed scoring chances.

Mt. Blue, playing into the wind in the second half, began possessing the ball, led by Sam Smith, Josh Smith and Gurney.

“We want to keep the ball on the carpet and play to feet, and in the second half, the wind definitely helped us do that,” Joel Smith said.

Brunswick goaltender Jack McDiarmid was called on to make four tough saves in the second half. His best stop came on a high rising shot by Jared Fontaine, with the netminder rising to get both hands on the ball.

There was little McDiarmid was able to do on the game-winning goal. Sam Smith sent Marshall toward the net, with the junior netminder coming out to cut off the angle. But Marshall’s shot rang off the crossbar and settled into the net with 11:05 left in regulation.

“At the half we were up 1-0 and we knew that we had to bring our all in the second half,” said Marshall. “We tend to play scared, but today we held it together. It was huge to get that second goal, and we were able to pull together.”

“Credit the guys. They had a lot composure,” Joel Smith said.

Brunswick pushed everyone forward, trying to find the equalizer. Horch saw two shots in a five-second span ring off the post to the left of Xander Gurney, keeping the Cougars in the lead.

Mt. Blue broke out of its defensive zone, led by Eli Yeaton, who passed to Sam Smith. A collision with McDiarmid left the Brunswick cage vacant, and Marshall scored with 2:50 remaining.

“I was able to get one, and the second was great, allowing us to celebrate a little,” Marshall said.

Mt. Blue now faces its toughest challenge, with the talented Blue Devils awaiting.

“We need to play composed and not let the moment get ahead of us. Lewiston is a great team and will bring everything they got. We have to have a great game,” Joel Smith said.