The Duke University-bound senior had four goals and three assists in York’s quarterfinal win over Freeport last week, and followed that with three goals and one assist as the top-seeded Wildcats had little problem with No. 4 Leavitt, winning 4-0, in Monday’s semifinal round.

“Leavitt is a great team and it was a great game,” Posternak said. “I just think we really played hard today and it showed on the scoreboard. I am just proud of how we played.”

York (16-0) advances to its ninth straight regional championship and will face No. 3 Yarmouth on Wednesday at Massabesic High School. Yarmouth advanced with a 2-1 win at Kennebunk on Monday.

York has won 52 straight games, a streak that dates back to its 2013 Class B state championship loss to Nokomis.

“It’s not an easy task to be able to (reach the regional championship) and we’ve been able to do that over the last few years,” said York head coach Barb Marois, who has led the Wildcats to Class B state championships in 2008, 2014 and 2015. “It says a lot of what this team is able to do and how focused they are, and how determined they are to get back and not take it for granted.”

York beat Yarmouth 3-1 during the regular season. York and Yarmouth, going back through 2010, have not faced each other in postseason play.

“Yarmouth is a skilled team,” Marois said. “We played them in the regular season and it was a pretty competitive, back-and-forth game.”

This was the fourth time in five years that York and Leavitt had met in the postseason. The Wildcats beat the Hornets 3-1 in last year’s regional championship at Fitzpatrick Stadium in Portland. Leavitt beat York, 1-0, in the 2012 regional final en route to its state championship, and York beat Leavitt in the 2013 semifinals, 2-1.

“I think (Leavitt) may be sick of us,” Marois said. “When you get to this level, you know the competition is there and I think they were competitive. We just had some really nice goals and we were able to capitalize early. I think when you can do that, that allows us to settle in and put a little pressure on the other team. They always have a strong team and a strong program.”

The Wildcats struck for the game’s first goals within 71 seconds in the opening seven-plus minutes of action.

Junior Sydney Bouchard, receiving a pretty pass from Posternak, turned a penalty corner into the game’s first goal. Bouchard made one move to her right and fired a shot past Leavitt goalie Hailey DeMascio (six saves) for a 1-0 lead with 24:03 left in the first half.

York struck again on its next penalty corner opportunity as Posternak took the entry pass from fellow senior captain Izzy Bretz and fired a one-timer past DeMascio with 22:29 left in the half.

“Those two goals certainly makes a difference,” Leavitt head coach Wanda Ward-MacLean said. “Them scoring two quick ones like that kind of puts you back on your heels and everybody was like, ‘Oh, no. What just happened?’ It’s hard to come back from two goals, but I thought we played pretty well the rest of the way. I was proud of the way we played.”

It was the start that both Posternak and Marois wanted.

“I think we came out really strong, and it was good to see everyone just pour their hearts into this game,” Posternak said. “Heading into the game, we really wanted to get on the board as fast as possible just to settle things down. I was so proud of (Bouchard) for putting that in right away. She’s been there all season for us and she definitely earned that goal.”

Added Marois: “In the other playoff game, it was a little while to put the ball in the net, so I think it’s always comforting as a coach, but also for the players, too; that enabled us to relax a little bit and settle into our game.”

Posternak added two goals in the second half, the first off an assist from Bretz. Posternak, a three-time All-State selection, now has 31 goals on the season and 84 in her career.

“I’ll be glad to see (Posternak) go, but sad as I won’t see her play,” Ward-MacLean said. “She’s an exceptional player and makes a huge difference.”

Leavitt’s only shot on York sophomore goalie Julianna Kiklis with came with 5:35 left in the first. Alana Hartford took an entry pass near the top of the scoring circle on a penalty corner and her hard, low shot was blocked by Kiklis and subsequently kicked away.

Kiklis was relieved by junior Julia Carr midway through the second half with the Wildcats enjoying a four-goal advantage. Carr didn’t see a shot.