STONEHAM  — Coming off consecutive years losing in the Div. 2 state boys hockey semifinals, Duxbury head coach Mike Flaherty didn’t know what to expect out of his team this year amid a rough start.

Now that their headed back to a third straight Final Four appearance after the No. 10 Dragons defeated No. 15 Masconomet, 3-1, in a state quarterfinal at Stoneham Arena on Thursday night, he can’t help but feel the proudest out of all three trips.

Cormac Weiler’s go-ahead goal late in the second was sandwiched by two from Brady Walsh, pairing with a standout defensive performance to gradually slow down a high-speed Chieftains’ attack. Chris Sacco impressed in net for Masconomet, but the Dragons got more than enough to face No. 11 Boston Latin for a trip to TD Garden.

“We made some adjustments and my guys just battled,” Flaherty said. “I’m so proud of them. If you asked me in the beginning of the year if this team would get back to the state semis – I don’t know. … For us to get back to where we are this year is probably the most satisfying.”

The up-and-down action of the first period was noticeably fast, something Duxbury studied prior but was still caught on its heels by. Within the first four minutes, Miles Mireault put Masconomet up 1-0 on a breakaway goal.

It didn’t take long for Duxbury to respond, though, with Walsh needing just four seconds of power play a couple minutes later to tie things up at 1-1. The Dragons adjusted defensively by locking on the wings on faceoffs and went to an 1-2-2 forecheck, effectively slowing Masconomet down to just 11 combined shots on goal in the second and third.

Sacco (30 saves) held off a barrage of shots from Duxbury in the meantime, but its third line potted the go-ahead goal with 2:28 left in the second when Weiler followed a rebound for his third goal of the year.

“Just going to the net for a rebound, ” Weiler said. “I knew my linemate was going to put it on net right from the faceoff.”

“Our three lines are all pretty equal,” Flaherty added. “We’re a little bit harder to defend in that way. … I don’t consider them the third line at all.”

As Masconomet struggled to get many shots on net with the game slowed down in the third, Duxbury just needed one more from Walsh with 4:51 left to put it away.

Michael Hussey and David Pittenger each had two assists, while Anthony Rabeni had 16 saves.

Now attention is turned on better fortune in the state semifinals.