Flyers goalie Steve Mason deflects a shot on goal by Jay Beagle of the Washington Capitals in the second period as Ivan Provorov skates in late in the Capitals’ 2-1 overtime win at Verizon Center. (Rob Carr/Getty Images)

The Washington Capitals’ power play was enduring one of its worst nights of the season, ineffective in its three opportunities during regulation. But on a four-on-three in overtime, defenseman Kevin Shattenkirk relayed the puck to Nicklas Backstrom in the right faceoff circle, and Backstrom sniped it in, all past struggles forgotten.

Though the Capitals’ power play ultimately delivered the 2-1 overtime victory, it was Washington’s penalty kill that starred at Verizon Center. Philadelphia’s power play remained scoreless against the Capitals on the season, adding six failed chances to its total Saturday night.

The win was the Capitals’ 15th straight at home.

“You know, in overtime, when it really mattered, when we had a chance to win the game, they responded,” Capitals Coach Barry Trotz said. “So, that’s how you look at it. I’ll take 25 percent any day of the week.”

After 40 minutes elapsed without a goal, each team tallied in the first three minutes of the third period. Philadelphia’s Sean Couturier redirected a pass in front from Matt Read to lift the Flyers to a lead 1:19 into the period. That lasted 81 seconds; on a rush into the offensive zone, defenseman Dmitry Orlov used Philadelphia’s Radko Gudas as a screen and fired a slapper past goaltender Steve Mason.

That set the stage for overtime, both teams getting at least a point out of the game. In three-on-three, Washington got a power play when Michael Del Zotto was called for holding with 2:40 left in the extra frame. A shot by T.J. Oshie hit Mason in the mask, popping the protection off his head. A little more than a minute later, Backstrom scored the winner.

To that point, Washington’s man-advantage had just one shot in three opportunities, perhaps still adjusting to a change in personnel with the addition of Shattenkirk, whom the Capitals traded for Monday.

“Sometimes you’re going to have these games [when] the power play is not going,” Backstrom said. “It’s a little bit frustrating. But at the same time, you just have to try to work through it and get better at it.

“We have a new player in there. It’s a lot of new things he needs to take in. I think when we’re all five are clicking, it’s going to look better, from the breakouts to the end zone and where we are. But I thought overall maybe it wasn’t our best game. Obviously the power play was struggling, too.”

Washington had its penalty kill to thank for the tie game at second intermission. The Flyers’ power play has the second-most goals in the NHL, and the Capitals didn’t help themselves by giving the unit six opportunities in the game. Philadelphia didn’t score on any of them, but Trotz still felt that it hurt momentum and the flow of the game.

“I thought there was a little bit of chippiness in there, but we’ve got to stay a little bit more disciplined,” Trotz said.

The Capitals are now 15 for 15 against the Flyers’ power play in the season series. With 13:42 left in a tied third period, Tom Wilson was called for roughing, and in the pivotal moment, Washington’s penalty kill allowed Philadelphia just one shot on goal. Orlov was whistled for high-sticking with 3:13 remaining in the third, and Washington’s shorthanded group killed that penalty off, too.

“It’s just recognizing that there’s not too many shots from the top,” forward Jay Beagle said. “It’s more of trying to spread us out and get it down low and then find either the guy in the middle there or back door. Our ‘D’ has done a good job at recognizing that and just trying to get a long stick on it.”

The Flyers entered the game just four points out of the second wild-card position, still vying for a postseason berth. Rather than sell off half the team before the trade deadline, Philadelphia General Manager Ron Hextall re-signed several players and added a piece in center Valtteri Filppula, trying to inject some hope into the team.

Trotz said he didn’t have to address with the team that the Flyers are a potential first-round playoff matchup for Washington; a look at the standings would make that evident. Saturday’s defensive, tight-checking and emotional game was a taste of what the Capitals could see in April.

“You’re going to get their absolute playoff-mode best game, and that’ll be a good test for you because that hardens us,” Trotz said before the game. “It gets us prepared for hopefully what’s ahead.

“This is my third year, and I have not been to a game where Philly and the Caps have not been a little bit nose to nose, so I think that’s a good thing.”