STANDISH — South Portland took half of the first quarter to score its first goal Tuesday night, but then dominated Bonny Eagle for a 15-1 victory in the Class A South boys’ lacrosse quarterfinals.

Fifth-seeded South Portland (8-5) faces top-seeded Thornton Academy on Saturday in Saco. Fourth-seeded Bonny Eagle, which was hosting its first playoff game since 2006, finished 7-6.

“This is what we wanted,” said Red Riots Coach Tom Fiorini, whose team started out 4-0 with wins over Scarborough and Brunswick before losing four of the next five. “We wanted to make a little noise in the game to make sure everyone knows that we are here for the playoffs, despite our seed.”

David Fiorini scored twice in a 1:08 span for a 2-0 lead with 6:42 left in the first quarter. Both goals came in transition – the first on a Cooper Mehlhorn pass across the crease and the second from Charlie Cronin.

Mehlhorn made it 3-0 before Fiorini again scored two quick goals.

Mehlhorn set up Fiorini’s third goal by picking up a loose ball after a hit at midfield. He carried the ball about 30 feet before finding Fiorini open on the opposite wing for a 25-footer.

Fifteen seconds later, with 59 seconds left in the quarter. Fiorini scored his fourth goal for a 5-0 lead when Cronin found him alone in front of the net following a faceoff win by Josh Doan.

“It took a little bit (of time) just to get our passing going, which is not normal for us,” said Fiorini, who finished with six goals and two assists. “Once we got that first goal we started to play catch and pass, and play lacrosse.”

Fiorini echoed his coach, and father, that this was a statement game for the Red Riots, who lost to Scarborough in a rematch late in the season.

“We shot ourselves in the foot (during the regular season) and ended up with the lower seed,” he said. “We had to come out and prove that we are not a fifth seed.”

Mehlhorn chipped in with two goals and two assists and Aidan Schifano and Alex Stevens both scored twice for South Portland, which led 11-0 at the half.

Riots goalie Quinn Watson made six saves, but lost the shutout with 4:02 left in the game when Anthony Breton scored on a man advantage.

“Quinn made some amazing saves today and the defense played very well. We are going to need that against TA,” David Fiorini said.

Bonny Eagle Coach Andrew Slefinger attributed the lopsided score to higher-quality players for the Red Riots.

“Tom has a very good (and) talented group of kids,” he said. “That isn’t to take away from our kids, but when you have key players like Cooper, David and Aidan it really makes it difficult. And we were going against one of the top goalies in the state who made a couple fantastic saves.”

Mehlhorn and Fiorini will give the Golden Trojans – who beat the Red Riots 14-4 on May 23 and ended their 2017 season with a regional semifinals victory – all it can handle.

“It is very difficult to control those two,” Tom Fiorini said. “They are very talented players who play very differently.”