Behind a goal and an assist from Jessica Mazo, St. Joseph High shut out Brien McMahon, 2-0, in the quarterfinals of the FCIAC girls soccer tournament on Thursday at the Dalling Sports Complex.

The second-seeded Cadets (14-1-2) overcame a sluggish start, with Mazo setting up Maddie Fried for the game-winning goal with 6:16 left in the first half.

“I really thought for twenty minutes in the first half they were playing better than us,” St. Joseph head coach Jack Nogueira said. “Once we scored the first goal, we weren’t as nervous and we started playing a little bit better.”

Mazo then sealed the victory in the 52nd minute, converting a bobbled save attempt by Senator keeper Kayla Cocchia.

Seventh-seeded McMahon (8-4-5) squandered a pair of scoring opportunities in the first half. After Cadet Julie DiCesare cleared a Senator shot off of keeper Grace Hickey’s goal line, McMahon had a breakaway opportunity.

At the 13:26 mark of the first half, Peyton McNamara raced through the midfield. She fought off the tackle attempt of Cadet defender Helen Mahoney, kept her feet, but hooked the shot wide of the frame.

McMahon produced another quality chance with 34:18 left to play.

Hailey Vechiarelli fouled Senator Viviana Luna just outside the 18-yard box, giving McNamara a direct kick out in front. St. Joseph lined up an eight-player wall, shrinking the target for McNamara — who drove the ball wide.

“Today was about we finished our opportunities,” Nogueira said. “They had a couple of opportunities that they could’ve finished, they didn’t.

“We found a way to win a game that was a very tough game for us. They made it tough for us, they defended… I’m happy with the result.”

After Mazo doubled the St. Joseph margin with 28 minutes left, the Cadets were able to successfully see out the match and punch their tickets to the semifinals.

In the final five minutes, St. Joseph wisely dribbled out wide to the corner flag, keeping the Senators hemmed to one side of the field.

“We practice that,” Nogueira said. “We’re trying to stall the ball and be defensive. We want to make sure we don’t get caught up in counters.”

That led to McMahon receiving a yellow card late, a culmination of the rugged play typical of a tournament setting.

“We dealt with it well today,” Nogueira said. “It’s the FCIAC, every game is like this… We’re not a physical team, we tend to not be as physical. It’s something we have to deal with and we try to play through it.”

St. Joseph will face the winner of third-seeded Ridgefield and sixth-seeded Trumbull on Monday in the semifinals.