BIDDEFORD — Yarmouth High killed off a pair of early second-period penalties that changed the balance of Wednesday night’s boys’ hockey game and produced a 4-1 win over Thornton Academy at Biddeford Ice Arena.

“We worked on our penalty kill all week in practice because we let up a power-play goal a couple games ago,” said Yarmouth Coach David St. Pierre. “While we’d been doing well on the P-K, we wanted to tighten it up a bit. It comes down to heart and compete level and that’s been one of our monikers are all year.”

Added Thornton Academy Coach Jamie Gagnon: “We had a couple good looks on the power play. We certainly had an opportunity to get back in the game and we didn’t capitalize. Whenever you get a power play, if you’re able to put one away it changes momentum. If they’re able to kill, it ends up being a momentum building opportunity for them.”

Sophomore Dan Latham, who helped the Clippers improve to 7-0, turned away some tough shots while his team was short-handed. And a defensive unit led by senior captain Walter Conrad did a nice job of cycling the puck away from the net.

“They’ve got a really good goaltender,” Gagnon said. “We got some pretty good looks; a couple breakaways. In the third period we started to run our offensive sets better and held position for a good part of that third period, but again, he made some great saves. They also did a great job of flooding the slot so there just weren’t any second- and third- chance opportunities.”

Anders Newberg’s first-period goal, set by Tyler Veilleux and Patrick Grant, proved to be as important as Yarmouth’s penalty-killing efforts.

“For us to be on the road and to go out and get an early lead like that just helped us settle in to our game plan,” said St. Pierre. “Getting on the board early was big.”

Minutes after killing the second power play in the second period, Yarmouth made it 2-0 on the power play. Grant cycled a puck toward the top of the offensive zone to Conrad, who blistered a drive through traffic and into the net.

With just under four minutes to go in the period, Chris Romano buried a wraparound chance after Thornton goalie Seth Dube made a pair of great saves, the second of which sent him sprawling to the ice.

“We didn’t come in here and expect to be able to get goals in bunches,” said St. Pierre. “We expected to have to come in here and grind it out, and that’s what we did. They’re a very talented team, and we did get some looks because we worked hard for them and were able to bury a few.”

Thornton (4-3) got one back a minute later when Nolan Millett unleashed a drive from the right circle into the top left corner to make it 3-1, and Noah Grondin sealed the win in the final minute of play with an empty-netter from the blue line for the Clippers.