AUBURN — Will Desmarais hadn’t thrown a pitch in a varsity game in two years — and had never started one on the mound in high school — when he got the starting nod for arguably the biggest game of unbeaten St. Dom’s season against the No. 2 team in the Western C Heal Points, Monmouth.

The Mustangs didn’t give Desmarais much time to settle in. A three-pitch first helped him a little, but then a three-run second put the Saints in a hole.

But Desmarais had an ace up his sleeve. Actually, more like a deuce.

Desmarais’ curve ball kept the Mustangs off-balance the rest of the way, and the Saints, led by Desmarais’ two hits, two RBIs and two runs scored, rallied from an early 3-1 deficit to defeat Monmouth, 7-3, in an important MVC matchup on Wednesday.

“I came in in relief in my freshman or sophomore year and just did absolutely atrocious, so I was a little bit nervous the first two innings,” said Desmarais, a senior who took a one-year hiatus to play lacrosse last year. “After that, I settled in pretty good. I’ve been working on (the curve) a lot in the bullpen and getting comfortable throwing it for a first-pitch strike.”

Desmarais threw a lot of strikes overall, not just on the first pitch. Of his 94 pitches, 69 went for strikes. He allowed four hits, fanned eight, walked one and hit a batter.

“We pulled a guy out of retirement today who hadn’t pitched in three years,” St. Dom’s coach Bob Blackman said. “We threw a bullpen (session) on Saturday for the first time and I introduced him to the cutter (fastball), and we worked on that a little bit and the two-seamer (fastball), but ultimately the hammer was there today.”

“We just didn’t make adjustments to the off-speed,” Monmouth coach Eric Palleschi said. “Will did a great job. He kept us off-balance, made us hit curve balls and we just didn’t hit them. We didn’t stay disciplined enough to stay back, keep our hands back and drive the ball.”

After his 1-2-3 first, Desmarais gave himself a 1-0 lead in the bottom of the frame with a sacrifice fly to score Zak Johnson (2-for-3, two runs, two RBIs). But an error in the second opened the door for Monmouth’s only runs, which came home on Devin West’s RBI single, Phil Rowe’s RBI triple and a wild pitch.

St. Dom’s (8-0) scored single runs in the second and third to tie it on Mike Richard’s run-scoring single and Mitch Lorenz’s sacrifice fly.

Desmarais scored the winning run after reaching on a fielder’s choice with one out. Jimmy Theriault’s hit-and-run single got him to third, and he scored on Lorenz’s grounder to second.

Monmouth (6-2) otherwise squelched the Saints’ running game and kept the defensive mistakes to a minimum, but a misplay at shortstop on what looked to be a double-play ball cost them in the sixth. The error set up Johnson’s two-run double and Desmarais’ RBI single to give the latter more than enough insurance when he returned to the mound.

“That’s a big win for us,” Blackman said. “We’ve faced the tough ones. We’ve got Spruce (Mountain) on Saturday, which will be another test.”