When the buzzer sounded on 18th-seeded St. Joseph’s 9-2 victory in the Class S boys lacrosse state tournament semifinal win over East Catholic from Manchester, the third-seeded Eagles had nothing left to do than throw their hands up in frustration at the goaltending display put on by the Cadets’ Cillian Donahue.

Donahue stopped 10-of-18 shots, none of the easy variety, as St. Joseph (12-8) advanced to the finals on Saturday to play top-seeded Somers High at Brien McMahon in Norwalk.

The Spartans (18-2) defeated fourth-seeded Granby High, 12-10, in their semifinal.

St. Joseph went 8-8 in the regular season, and has been tough to defeat in the postseason.

The Cadets defeated No 15 Montville 22-3 in a qualifying game, before knocking off No. 2 Old Lyme (14-11), No. 7 North Branford (17-5) and East Catholic.

“Our goalie, Cillian Donahue, has been the backbone of our defense, we told the kids not to waste his talent,” St. Joseph head coach Brendan Talbot said of his senior netminder. “We have a really good goalie, if we give up shots that he can save it’s going to take us far.”

East Catholic was first on the scoreboard.

Connor Goldberg survived a hard check and scored at 9:46 of the first period.

Jared Newall scored the first of his three goals to tie the game at 9:46 of the first.

Kevin Trefz turned the Eagles over in the defensive end and Matt Labash assisted on Newall’s tally.

St. Joseph had the next eight goals, before Connor Hills tallied for the Eagles to make it 8-2 with 4:39 remaining in the third.

“Our entire defense is all juniors, our attack is sophomores and juniors,” Talbot said. “The team as a whole was dynamite today.”

Brian Harner, Kevin Faustich and Colin Daly provide the first line of defense for the Cadets, giving Donahue a good look at his attackers.

“We were just looking to grind, coming into the game,” Donahue said of the defense’s mindset. “It’s the last two games (semis, finals), just give it your all, leave nothing in the tank.”

He has confidence in his defensive mates.

“To be honest we were all on the jayvee team, so we’re all familiar with each other, we all worked together,” he said. “We know what we were strong at, worked to get better, then stepped up to the next level. I guess it’s working.”

Chris Klabonski, Liam Seperack, Nick Celentano, Liam McGinley, Brandon Zinnoch hounded the Eagles in its offensive zone, while Newall, Ryan Wilson, Jared Mallozzi and Liam Massey waited to strike.

Harner forced a turnover, Daly scooped up the ground ball, and Faustich set sail in transition, where he whipped home a goal at 4:07 of the first for a 2-1 lead.

Seperack, Harner and Trefz hit everyone that moved to slow the Eagles over the next two minutes.

On the offensive end, Newall patiently waited for a pattern to form and found a cutting Klabonski to extend the lead to 3-1 at 1:34.

Donahue made a sprawling save on Trevor Wilcox’s low shot to open the second period.

Down the other end, Mallozzi made a great bounce shot that beat Aric Graves two minutes into the frame.

Donahue deflected a shot wide by Hills at 9:10, but East Catholic kept the pressure on the Cadets.

An unforced error gave the Eagles possession at 8:30, but Jake Tellers was called for a crease violation and his goal was disallowed at the eight-minute mark.

Following a defensive stop, East Catholic called for timeout with 6:29 looking to turn the momentum shift into a closer contest.

Hills unleashed a tough shot, but Donahue was glued to the post and the only opening was in the side netting.

Graves deflected one Cadet shot and made a dazzling save on the same possession.

The tightly-played quarter seemed to be coming to an end.

Not so fast.

Harner forced a turnover and Wilson turned the corner on the defense.

The sophomore’s goal with four seconds on the clock took the score to 5-1 going into the half.

“In the first half we ran our offense pretty well,” Talbot said. “Give them credit, they made some adjustments to force us out of our game. We tell kids we can’t just score six on six, we have to score other ways as well.

"In the second half I think we scored three or four goals off rides, picking off passes, getting ground balls and pushing it.”

As he did in the second period, Donahue was ready from the opening whistle in the third stanza where he deflected a Wilcox shot wide.

One minute later, the Eagles forced an errant pass.

On the clearing attempt, however, Wilson doubled back to grab the ball out of the air and fired it into an empty net for a stunning goal.

St. Joseph led 6-1 at 8:41 of the third.

Less than a minute later, Newall scored again off an assist from Wilson.

Treftz then turned a forced turnover into a long run by the senior into the Eagle zone.

Newall was waiting on the wing, took Treftz’ pass and fed Klabonski all alone in front for an 8-1 advantage.

The Eagles’ Hills broke the eight-goal Cadet skein, but there wasn’t going to be an East Catholic run.

Donahue made a great save on Wilcox at the 2:48 mark and St. Joseph took an 8-1 lead into the fourth period.

Chris O’Connor came on in goal for the Eagles and continued the fine play by rival netminders, as he made four fine saves.

Mallozzi assisted on Newall’s goal at 8:10 of the period to complete the scoring.

Donahue had stops at 11:31, 6:16, 3:15, and :26.

Was it easy for him to stay focused with the large lead?

“Absolutely,” he said. “It’s always good to turn around and not have to pick the ball out of the net. It’s the one thing as a goalie you don’t want to do. As much as I can stop the ball from going in there (the net), the happier I’ll be.”

Talbot said: “We knew they were a good offense, we really didn’t expect to hold them to two, we  thought it was going to be a higher scoring game than that. It’s just a credit to the kids out there.

"Now we have an opportunity on Saturday, and that’s all it is. Get ready for Somers or Granby.”