SCARBOROUGH – Jon Blaisdell scored five goals and top-ranked Scarborough did the rest with defense Saturday in a Western Class A boys’ lacrosse semifinal against Marshwood.

Scarborough, the defending state champion, consistently kept fifth-seeded Marshwood from even getting started on the way to a 12-3 victory.

Scarborough (12-1) will be home against third-ranked Thornton Academy (11-3) at 4 p.m. Wednesday in a rematch of last year’s regional final.

Blaisdell scored with 40 seconds left to give Scarborough a 5-2 halftime lead. He and Ryan Pallotta scored in the final 1:10 of the first quarter.

“Those last-minute goals that put us ahead, they pushed us over the edge and gave us the momentum going into the next quarter,” Blaisdell said.

In the second half, Scarborough asserted itself with a defense led by goalie David Pearson, and long-stick middies Brett Leighton and Andrew Jones.

Marshwood (8-6), which won one game over the past two seasons, repeatedly had clearing attempts intercepted or knocked down.

“Their ride on our clears was stifling and we couldn’t get our middies back quickly enough to help out,” Marshwood Coach Ralph Ruocco said.

“Because we’re an athletic team, we coach an aggressive style,” Scarborough Coach Joe Hezlep said. “We’re willing to take chances other teams won’t because we can recover. Our philosophy is make the play and if you don’t, make the next one.”

John Wheeler had four assists for the Red Storm, two to Blaisdell.

“What’s funny is not a lot of people really talk about Blaisdell,” Hezlep said. “Where with Wheeler, everyone knows he’s a threat. A lot of people are focusing in on Wheeler and (Blaisdell) is taking advantage of every chance he gets.”

Scoring for Marshwood were Rich Crowley (1:22 into the game for a brief 1-0 lead), Zach Webster and Andrew Rollins. Rollins’ goal made it 7-3 at the end of three quarters.

“We’re ecstatic with our season, coming from one victory last year and no victories the year before,” Ruocco said. “Going 8-6 is a giant step for our program, but we know we have a lot more ground to cover to get to the level of teams like Scarborough.”

Scarborough scored five goals in the first six minutes of the fourth quarter.