BOSTON — Washington Capitals Coach Barry Trotz doesn’t want to give Matt Niskanen too much credit for his sudden surge of winning goals.

“He’s on the ice all the time, that’s probably the No. 1 (reason). The odds go up when you’re on the ice,” Trotz said after his defenseman scored 2:36 into overtime to give the Capitals a 2-1 victory over the Boston Bruins on Saturday night.

“He doesn’t get credit for what he’s done,” Trotz said. “But he’s one of the most popular guys in our room.”

Niksanen scored on a slap shot from the blue line for his second winner in three games and his third of the season. Philipp Grubauer stopped 33 shots and Karl Alzner also scored for Washington, which has won three of its last four games.

“I had just enough room to get a slapper off from up top,” said Niksanen, who was on the ice a game-high 26 minutes, 48 seconds. “Somehow it found its way in.”

Niksanen’s last goal gave the Capitals a 3-2 victory over the Toronto Maple Leafs on Wednesday. After that, they lost to the New York Rangers on Friday night, then got to bed in Boston on Saturday morning at about 3 a.m. for their fourth game in five days.

The Capitals have lost back-to-back games just twice this season. They will now have to see if NHL-leading goal-scorer Alex Ovechkin is suspended after a 5-minute boarding major that dropped Boston’s Kevan Miller to the ice and sent him to the hospital.

“It’s just a hockey play,” Ovechkin said. “You don’t want to be in position to take a penalty, but the referee said I get 5 minutes because I was heavier than him.”

Patrice Bergeron scored Boston’s only goal and Rask made 28 saves for the Bruins, who had won two straight and four of five. Despite the loss, the Bruins picked up three of a possible four points in back-to-back games against the Western Conference-leading Chicago Blackhawks and the East-leading Capitals.

“I think we’re playing better, but there’s always room to improve,” defenseman Zdeno Chara said. “It’s not getting any easier, and we have some tough games ahead of us.”

The Bruins made it 1-0 with 7:11 gone in the game when Brad Marchand swung it to Bergeron in front for the goal. A second potential Boston goal was taken off the board in the second period after Washington challenged and the linesman agreed that Loui Eriksson was offside on the play.

Washington tied it 1-all with 7 minutes left in the second when Ovechkin passed across the ice to Nicklas Backstrom, who sent it back the other way to Alzner in front. Later in the second, Ovechkin picked up his first major penalty of the season when he hit Miller from behind against the boards.

Boston’s power play was cut from 5 minutes to 3 because Marchand picked up a roughing penalty. The Bruins got a 5-on-3 for the last 1:49 after Tom Wilson was called for interference, but they were unable to convert.

“That was a huge kill,” Washington forward Jay Beagle said. “A kill like that, it’s a huge momentum swing.”