Winny Brodt Brown, the Whitecaps’ 42-year-old defender and team leader, had a message during the overtime intermission after Minnesota and the Metropolitan Riveters played a scoreless 60 minutes in their NWHL semifinal Sunday at Tria Rink. Her day job of director of Os Hockey was calling.

“I go, ‘Girls, I got to get to the rink in a couple of hours. Let’s get this thing done,’ ” Brodt Brown said.

Turns out, the Whitecaps had just the player who can make things happen quickly: Allie Thunstrom.

Thunstrom, a former speedskater, turned on the jets and led a three-on-one rush into the Riveters zone. After dishing off to Jonna Curtis, Thunstrom took a return pass and poked the puck past Metropolitan goalie Sam Walther at 6:39 of overtime to give the Whitecaps a 1-0 victory and set off a raucous celebration.

“Somebody on our roster was going to get [the winning goal],” said Thunstrom, who led the NWHL with 24 goals and was named co-MVP with Boston’s Jillian Dempsey. “There was no question whether or not we were going to walk away with the win.”

The Whitecaps, who won the NWHL title in their inaugural season last year, will play the Boston Pride for the championship on Friday night in Boston. The Pride (24-1) topped Connecticut 5-1 in Sunday’s other semifinal. Minnesota (18-5-2) is the only team to defeat Boston this season.

Getting back to the title game was no easy task, especially with Walther and the Whitecaps’ Amanda Leveille locked in a goaltending duel. Leveille, a former Gopher, finished with 25 saves. Walther made 24 and repeatedly foiled Minnesota’s odd-man rushes.

“She was phenomenal,” Thunstrom said of Walther.

The teams were evenly matched through three periods, with each killing four penalties. With about 30 seconds left in regulation, the Riveters’ Madison Packer held Sydney Baldwin, and the Whitecaps pushed hard for a goal on the delayed penalty call. Metropolitan got control of the puck with two seconds left, and Minnesota would open overtime with 1:58 of power-play time.

Though the Riveters killed the penalty, the home team was energized. “We were feeling it,” Brodt Brown said. “We had good momentum.”

At the 5:50 mark of overtime, the Whitecaps nearly won it on a three-on-one rush, but Walther made a scrambling save. That only delayed the inevitable.

“We knew we didn’t want it to go on forever,” Thunstrom said. “We said, ‘Let’s get in there in the first five minutes and put some pressure on and take this game away.’ We did a good job of that, starting with the power play.”

Thunstrom said the Whitecaps have the confidence to beat Boston. Brodt Brown believes they also have a special player who can make that happen.

“Thunstrom coming through as a hero all year long,” she said. “Hopefully, she has one more game in her.”