PORTLAND — When chaos reigned, so did Sierra Carson.

Facing a big deficit and not a lot of time left on the clock in Saturday’s Class AA North girls basketball final, Oxford Hills flipped the switch.

Carson led way as the top-seeded Vikings rallied back and out-dueled second-seeded Cheverus to win 68-63 in double overtime at Cross Insurance Arena.

“When we were down 10 in the fourth, we finally just said, ‘We need to cause as much chaos as possible,’” Oxford Hills coach Nate Pelletier said. “And that’s where (Sierra) thrives, in that sort of chaotic environment where she can use her athleticism, and she did. She found some open shooters when we needed to, she went to the rim, made free throws, and, geez, that was awesome.”

Oxford Hills (20-1) will face Gorham (12-9) in the Class AA state title game next Saturday at 7 p.m. at Cross Insurance Arena.

Carson, a senior, scored 24 of her 29 points in the fourth quarter and two overtime periods in Saturday’s regional final. She helped the Vikings battle back from a 12-point fourth-quarter deficit and then teamed up with Tristen Derenburger in the second overtime to finally secure the victory and the region championship.

“Sierra’s one of the best players I’ve ever coached against,” Cheverus coach Bill Goodman said.

The Stags (18-3) took a four-point lead in the second overtime. Carson cut the deficit to three with a free throw, and, later, after an Oxford Hills miss, she stole the ball back and dished the ball back to Derenburger for a game-tying 3-pointer.

“We shot before we came here at school, and I really just knew, if I get a shot, whether it’s one or two, I have to at least make one of them,” Derenburger said. “And then, at the end, (Sierra) had faith in me, and they stopped face-guarding me, and I was like, this is the time … when I need to lock down and be there for my teammates.”

The Vikings made another defensive stop, and Derenburger put them ahead for good with another 3.

“I can’t say enough about our whole team, the effort,” Pelletier said. “We have Tristen Derenberger, who has shot the ball really well for us all year, struggled a little bit in the playoffs, but she hit two 3s in that second overtime — one to tie it, one to put us up three — that pretty much won us the game.

“But that’s what she’s been all year, we just had to get her in the rhythm of her shot. The second one, she was even guarded, and I think she just wanted to win the game. It was huge.”

Carson then locked up the win by going 4 for 4 at the free-throw line.

“She had a couple looks in one of the overtimes to win it. I’m glad that she hit those big free throws in the end to seal it for us,” Pelletier said. “It was huge.”

Ella Pelletier, who fouled out in the first overtime, scored 17 points for Oxford Hills. Derenburger made three 3-pointers in the game and finished with nine points.

Maddie Fitzpatrick led Cheverus with 28 points, including 15 after the third quarter. Emma Lizotte added 15 points.

Cheverus scored the first six points of the fourth quarter to go up 41-29 with 6:39 remaining in the game.

Desperate, the Vikings started to press more aggressively in an attempt to counteract the Stags’ size.

“We knew that we could still win,” Oxford Hills senior Molly Corbett said. “We had that mindset that we were still going to win, we were still going to push. We knew we could still do this, no matter how much time was left.”

Over the next two minutes, Carson led Oxford Hills on a quick 9-0 run that got Cheverus’ lead down to 41-38 with 4:39 left.

“The one thing I know about my team and these girls is that they will never give up,” Nate Pelletier said. “So all it took was a couple made baskets through that chaos we were creating, and once we cut it to, like, eight, it was like, we’ve got a chance here, we’ve just got to keep working at it.”

Less than 20 seconds later, Ella Pelletier was called for her fourth foul, and went to the bench for about a minute of game time. With 3:28 to play, Oxford Hills’ Gabbie Tibbetts picked up her fourth foul.

The Vikings eventually took the lead. A 3-pointer by Tibbetts cut the deficit to 47-46, and then Carson hit all three free throws after being fouled on a 3-point attempt to put the Vikings up 49-47 with 1:23 remaining.

But Cheverus also wasn’t ready for its season to end, and Fitzpatrick rebounded her own missed shot and scored in the final minute to force overtime.

“They’re so good. They are so good,” Carson said of Fitzpatrick and Lizotte. “Like you know that you’re not going to completely shut them down, it’s just limiting them.

“Gabbie Tibbetts and Ashley Richardson, they did so good at doing their face-guarding, containing them. Even when they get those fouls, it still helped because they were limiting them.”

Tibbetts, a sophomore, also hit a 3 during the comeback. That might have been her second-most memorable 3, behind the one she made at the end of the first half when she knocked down a pass, chased down the ball and heaved an off-balanced shot into the basket before the halftime buzzer.

Carson, who will play at Dartmouth starting next season, scored 13 in the fourth period.

“I think what got her going is she didn’t want to see her season end. That’s what a senior does, they come up big in big moments,” Nate Pelletier said.

Fitzpatrick, a junior committed to play at the University of Maine after high school, scored eight in the fourth.

Carson opened the first overtime with a 3, but Ella Pelletier fouled out with 1:21 left and Maddy Miller fouled out with 12.9 seconds left, and the first extra period ended with the score 49-49.

Ella Pelletier and Miller fouling out meant Oxford Hills had nobody who could come close to matching the height of Fitzpatrick and Lizotte. In fact, Carson, the Vikings’ point guard, moved into the post to defend Lizotte.

The all-guard lineup, however, meant Oxford Hills could ramp up the pace even more.

“It actually made us be able to create more chaos with more guards on the floor, because, literally, we had so much speed on the floor at that time that it was really hard for (Cheverus) to just go by,” Nate Pelletier said.

The Vikings survived to force another overtime and then survived in the second extra session to return to the state final. Oxford Hills won the 2019 and 2020 Class AA championships.

“They really want to go after that gold ball,” Nate Pelletier said. “This was a stepping stone to that.”