It wasn’t pretty, but Queen’s finally beat the defending Yates Cup champions — with massive help from their defence.

The nationally second-ranked Gaels beat the sixth-ranked McMaster Marauders 31-24 on Monday at Richardson Stadium, hanging on for their first win over McMaster since 2009.

Queen’s built a 21-point lead in the fourth quarter — then nearly squandered it in the last 10 minutes, a scene reminiscent of several 2012 contests.

Gaels head coach Pat Sheahan said both teams could give better performances than they did on Monday.

“There’s no question that we can play better than we did today,” he said. “It was a game of mistakes and the team that made more of them lost.”

The Gaels’ defence provided a boost in the second half, with Yann Dika-Balotoken leading the way.

The third-year defensive back intercepted McMaster quarterback Marshall Ferguson for a pair of touchdowns — one a 99-yard return in the third quarter, the other from 70 yards out in the fourth.

The scores turned Queen’s 11-7 advantage at halftime into a 31-10 lead with 12 minutes remaining.

“Without those two big plays, we don’t win the game,” Sheahan said. “It gave our entire team a lift.”

The defensive touchdowns were crucial in a game where Queen’s offence struggled to get going.

Quarterback Billy McPhee was unable to find his rhythm, completing 14 of 29 passes for 114 yards and throwing one interception.

Leading rusher Ryan Granberg was held to 26 yards on 11 carries, while the offence saw 10 drives end in two-and-outs. Only one of Queen’s four fourth-quarter drives resulted in yards gained.

“Our ball control on offence left quite a bit to be desired,” Sheahan said. “This is two weeks in a row we didn’t run the football very well and we’ve got kids who can run it.”

Meanwhile, McMaster found their offensive rhythm, scoring twice in the final frame before the Gaels forced turnovers on the Marauders’ final two possessions.

Locked in a defensive stalemate, neither team was able to gain an advantage in the first half, each managing only a single big offensive play.

For McMaster, it was a 73-yard touchdown reception by slotback Daniel Vandervoort, who slipped untouched behind the Gaels’ secondary in the second quarter.

Queen’s touchdown came three minutes later, when receiver Doug Corby pounced on running back Jesse Andrews’ fumble in the end zone. It was the Gaels’ only offensive touchdown of the game.

“Possession is so key in a game like this — that’s basically what it comes down to,” Corby said. “I saw [the ball], got it and the end zone’s right there.”

Alongside their strong defence, Queen’s benefited from an undisciplined McMaster squad that committed 13 penalties, four of which gave the Gaels a first down.

The win keeps Queen’s tied atop the OUA standings with the Guelph Gryphons and Western Mustangs at 2-0. McMaster falls into a four-way tie for fourth at 1-1.

Queen’s will face the Windsor Lancers (1-1) at home tomorrow at 1 p.m. The Lancers fell 24-23 to Guelph on Monday, losing on a field goal with three seconds left.