STANDISH — Extra-base hits sparked St. Dominic Academy into its third straight Class D baseball state final with a 12-4 win over Richmond in the D South title game Tuesday at St. Joseph’s College.

The top-seeded Saints had three doubles and one triple that drove in runs.

“We have some big boys on this team,” said Thomas Casserly, who hit one of the run-scoring doubles. “They can put the ball in play and they hit it hard. It shows and it helps. That’s how we win games.”

St. Dom’s (17-2), which has won the past two state titles, will face North champ Stearns in the Class D final Saturday (1 p.m.) at the University of Southern Maine in Gorham.

“It’s exciting, the feeling never stops,” Casserly said of returning to the state championship game. “It’s the same every time, and I am excited to be there.”

St. Dom’s offense quickly got to work Tuesday. A couple of players reached base in the first inning, but Richmond (15-2) starter Wyatt Cassidy got out of the early jam when his infielders turned a 4-6-3 double play to end the frame.

The Saints again had two base runners in the second inning, and this time they capitalized.

Ben Dumais plopped the ball into right with one out, and Curtis Wheeler walked. Both came around to score on Casserly’s double to center field.

“I had two guys on base, and I was like, you have to get them in somehow,” Casserly said. “The pitcher, he’s a really great pitcher, I just got lucky putting the bat on the ball.”

Back-to-back walks loaded the bases for Ouellette. Cassidy struck him out, and the Bobcats tried to pick off Casserly at third, but the throw went into left field, which allowed Casserly to score for a 3-0 St. Dom’s lead.

Richmond coach Ryan Gardner said the Bobcats made too many mistakes.

“This one came down to the 12 free passes we gave them,” Gardner said. “Nine walks and three hit batsmen. When we did that — I will give them credit, (Ridge) Dionne ripped one and Tim (Ouellette). … Free passes in playoffs don’t work.”

Saints starting pitcher Ashton Hammond retired the first seven batters he faced. Richmond’s David Edwards ended that streak in the third inning when he snuck a single into the outfield. He later moved to third on Jacob Gay’s bunt attempt after the throw to first went into right field.

“The bottom (of the order) came ready to play today,” Gardner said. “Jacob Gay had great at-bats. Up and down our order, the kids love to play and they compete.”

With two outs, Zander Steele doubled to right, scoring Edwards. Kenny Mecham knocked home Gay and moved Steele to third. Mecham stole second base to put two runners in scoring position, but Hammond escaped with an inning-ending strikeout.

Casserly nearly drove in another run in the Saints’ half of the third. He smacked the ball into right field, but Edwards tracked it down and made an on-target throw that got Dumais out at home.

Hammond struck out the side in the fourth.

In the bottom half of the inning, Hammond was on second base when Ridge Dionne blasted the ball to the warning track to score Hammond.

“Execution — like I said, that’s what we worked on in practice this week,” St. Dom’s coach Bob Blackman said. “Being short to the ball and put it into play. We knew their first pitcher was going to throw hard, but it’s not like we haven’t seen guys just like him.”

After St. Dom’s Ethan Pelletier got hit by a pitch, Riley Daigle doubled into the gap in left to bring in Dionne and Campbell Perryman, who pinch-ran for Pelletier. Daigle came around to score after a pair of throwing errors, extending the Saints’ lead to 7-2.

“I wasn’t expecting it,” Daigle said of a throw when he reached third base. “But it got past (me) and Coach said, ‘Get up,’ and I ran.”

The Bobcats capitalized on a Saints mistake in the top of a fifth.

After Gay reached on a single, St. Dom’s tried a 4-6-3 double play, but a throwing error sent Gay to third and put Ben Fournier at first. A double-steal attempt resulted in Gay being picked off at third, but Fournier moved over to second.

Steele doubled home Fournier, and following a Mecham single, Steele scored on a throwing error to cut Richmond’s deficit to 7-4.

The Saints pulled away with a five-run fifth highlighted by Ouellette’s RBI triple.

“Five runs with one hit, too much to overcome today,” Gardner said.

Cassidy doubled for Richmond and Alexander singled in the top of the sixth, but they were stranded on the corners.

Hammond struck out the first two batters in the seventh before being relieved by Ouellette, who ended the game with a strikeout.

Hammond had 14 strikeouts against eight hits.

“It wasn’t our cleanest game, but I thought we played well,” Blackman said. “Ashton pitched well, and our plan was to put the ball in play, and we did that. I am very pleased with that part of it.”