YARMOUTH — Trevar Haefele won the opening faceoff and took off toward the Yarmouth cage. He reached the attack line, 20 yards short of the goal, and stopped. For nearly three minutes, he weaved in and out, trading passes with fellow senior Tim Day, brother Troy Haefele and the rest of the Saints’ front line.

Slowly and steadily, the ball rotated around the perimeter, but not once did St. Dom’s even sniff the front of the net.

One ball-down later, one quick turnover and one pass from side to side at the other end of the field, and Yarmouth rendered all of that time of possession absolutely useless.

The Clippers’ quick-strike offense, fueled by shifty attackmen Evan Henry and Steven Petrovek, wore down the Saints’ defense. Henry and Petrovek scored 10 of Yarmouth’s 18 goals as the Clippers defeated previously unbeaten St. Dom’s 18-5 in the Eastern Class B regional lacrosse championship at Yarmouth High School on Wednesday.

“A lot better than last year,” Saints’ coach Dave Haefele said with a shrug of his shoulders. The Saints lost to Yarmouth in the regional semifinals last season by a 26-1 count.

“We know they’re good, and what they got (early) was our mistakes,” Dave Haefele said. “We were trying something different, with a short-stick on Petrovek, and it was quite effective, really, but they’re so deep they had other guys to step up to the plate.”

The Clippers’ second weapon was Henry, who scored four of the team’s first seven goals, all in the first quarter.

“Our strategy is, if Steve is locked off, to bring our other attackmen below the net, that way three of their defenders would be out of the way, leaving above the goal open for dodges and driving,” Henry said. “We took advantage of that as much as we could, especially in the beginning of the game.”

Following the Saints’ lengthy opening possession, Yarmouth started to roll. Mike Johnson made it 2-0 at 8:38, and Henry struck again at 7:26.

After a timeout and a St. Dom’s tally from Trevar Haefele, the Clippers rattled off four in a row to close out the opening quarter.

“That’s a problem for other teams,” Yarmouth coach Craig Curry said. “If you’re going to faceguard one guy, it’s going to take a guy out of your slide package, and it opens it up.”

St. Dom’s managed to slow things down in the second, and nearly equaled the Clippers’ output. Yarmouth scored three times in the second to the Saints’ two, and took a 10-3 advantage into halftime.

“They do pass the ball really well, they move the ball,” Curry said. “Five or six of those guys can really play, but I think they only have those five or six kids, and that makes it a bit easier for our guys.”

There was no argument on that point from Dave Haefele.

“We didn’t have enough legs, really,” Haefele said. “We just stayed with our plan. We were really trying to limit their possessions and tried to keep it out of their hands as much as we could.”

In the third quarter, though, Yarmouth put the pedal to the floor, scoring three goals in the first two minutes to run the lead to 10, and the Clippers triggered running time with 7:25 to play in the third.

Still, the Saints remained patient on offense. Yarmouth had to work hard to avoid being too aggressive on defense.

“Our mistake would have been going out and creating penalties, because they had a nice little man-up,” Curry said. “We wanted to stay out of the box, and by playing as patiently as they were, with as good stick protection that they had, we stayed out of trouble.”

St. Dom’s and Yarmouth traded a pair of goals each in the fourth quarter to cap the scoring. Five different players — Trevar Haefele, Troy Haefele, Matt Adams, Anthony Fagone and Tim Day — scored goals for the Saints, who return the bulk of their lineup next season for another kick at the can.

“Last year was the first year in the playoffs, this year we made it here,” Dave Haefele said. “I think we can take it one more step. We have a little more depth this year, and we hope that’s going to keep growing.”

Yarmouth will face Cape Elizabeth, which handed the Clippers their lone loss of the season, in the Class B state final Saturday at Fitzpatrick Stadium in Portland.