GORHAM — Scarborough High’s big concern ended up providing its biggest opportunity Tuesday.

The Red Storm, who play their home games on the narrow 196-by-78 foot MHG Arena in Saco, found their way around the considerably larger sheet at the USM Ice Arena. USM’s rink is four feet longer and a full 22 feet wider than Scarborough’s home ice.

“We were very concerned. We’re used to working in a confined area,” said Scarborough Coach Norm Gagne. “There’s a lot of open ice here but I thought the kids adjusted well.”

Jack Rousselle looked downright comfortable, finding the room to set up two third-period goals as the third-seeded Red Storm slipped past sixth-ranked Biddeford 3-1 in a Western Class A boys’ hockey quarterfinal.

The Red Storm (13-4-2) moved on to the regional semifinals, where they will take on second-seeded Falmouth (14-4-1) at the Colisee in Lewiston on Saturday.

Falmouth advanced with a 10-1 victory against seventh-ranked Kennebunk.

“I told the kids, first, we needed to outgrit them,” Gagne said. “And second, when we got our opportunities, we needed to show composure near the net.”

Jordan Bathe gave Scarborough a 1-0 lead at 11:57 of the first period, finishing a pretty passing sequence from Trevor Murray and Jake Gross to beat Biddeford goalie Jon Fields (25 saves) for his sixth goal of the season.

“We made a couple of mistakes and they put them in the net,” Biddeford Coach Rich Reissfelder said.

“All year long we have never lacked effort. We’ve had bad bounces, been out of position or had bad luck. But these kids never lacked for effort.”

Tyson Nadeau tied it for the Tigers (7-9-3) with a short-handed goal at 8:49 of the second. He picked up an errant back pass at the Tigers’ blue line and outraced a defender to beat Dalton Finley (14 saves).

Cam Loiselle gave Scarborough the 2-1 lead just 35 seconds into the third.

The play started when an onrushing Rousselle slipped the puck between a defender’s skates, picked it back up and snapped a shot on Fields.

The rebound bounced to Loiselle, who lifted the rebound into the right corner.

Garrett McDonald beat Fields five minutes later, finishing off a Rousselle pass for a 3-1 lead.

“We had space to make passes and not force things,” Rousselle said.

“The first goal, (Loiselle) was there to finish. On the second, I saw the space to carry it up and a chip pass (to McDonald) was all it took.”

Scarborough, whose defense blocked a number of shots, then turned to its third line of Sean McGovern, Damian Ramsdell and Cam Brochu to hold off the Tigers.

Not everything worked the way Rousselle had hoped.

First, while his teammates marked the start of the playoffs with bizarre haircuts (Mohawks, various divots and even a Stooge Larry Fine lookalike) Rousselle went with “some sweet cornrows but they didn’t stay in.”

Then, with 7:43 to play, he was sent to the box with a 10-minute misconduct for unsportsmanlike conduct.

Scarborough went 0 of 4 on the power play; Biddeford was 0 of 2.

“He said something he shouldn’t have,” Gagne said. “He knows he made a mistake. He apologized. And he won’t make it again.”

And now it’s a rematch with Falmouth, which beat the Storm 6-0 on Feb. 23.

“They embarrassed us,” Gagne said. “With luck, we learned from that and can improve on it.”