PITTSBURGH -- Washington Capitals defenseman Matt Niskanen said shutting out the Pittsburgh Penguins for a third time would be a "unique kind of hat trick."
The Capitals were unable to accomplish that, but they continued their dominance of the Penguins on Tuesday.
Joel Ward scored with 4:13 remaining in the third period to help the Capitals defeat the Penguins 3-1 at Consol Energy Center.
It was Washington's third win in as many games against Pittsburgh this season; the first two were by shutout (3-0, 4-0).
After a slashing penalty against Penguins defenseman Kris Letang gave the Capitals a 5-on-3 for 1:49, Ward buried a cross-crease pass from Nicklas Backstrom behind goalie Marc-Andre Fleury to give Washington a 2-1 lead.
"[Backstrom] told me before to get closer to the net and be ready," Ward said. "I had a feeling something was going to come my way after him telling me that, and they kind of gave me a lane.
"It's no secret [about Ovechkin], they're paying close attention to him. … You get a chance and you just have to bear down. I was fortunate to get an unbelievable pass and I just had to make contact before the goalie could have gotten there."
Capitals defenseman John Carlson scored a shorthanded, empty-net goal with 11.4 seconds remaining.
Washington (31-17-10) is within one point of the New York Rangers and Pittsburgh for second place in the Metropolitan Division. The Penguins (32-16-9) are four points behind the division-leading New York Islanders, who defeated the Carolina Hurricanes 4-1 Tuesday.
"We weren't really sharp today, early," Capitals coach Barry Trotz said. "We would make one or two passes and then we would fumble it. We're a precision power play, for the most part, and we'd be precise for two or three passes. We weren't sharp in that area, but at the end of the day, it won us the hockey game. That's the bottom line."
Letang temporarily left the game 23 seconds into the third period after being slashed in his right ankle by Alex Ovechkin, with Ovechkin trailing Letang to the right corner behind the Pittsburgh net. Letang fell to the ice and slid into the boards, and was treated by a Penguins trainer.
"It was a battle and the puck was in his feet and I went to make a shot on net," Ovechkin said. "Unfortunately, he fell and hit the boards, but he's OK now. I don't think it was a penalty. The puck was at his feet. I went to take a shot and that's it."
Penguins coach Mike Johnston said he was proud of his players standing up for Letang, but said it led to them taking too many third-period penalties.
"The response from our team, I thought we fought back," Johnston said. "We competed for each other. It's a fine line, like we talked about, and you can't take four penalties in the third period against a team like that. You just can't do that."
Ovechkin gave the Capitals a 1-0 lead late in the first period. After a tripping penalty to Penguins forward Blake Comeau expired, Pittsburgh turned over the puck in the neutral zone during a line change. Ovechkin blazed by Letang, who had taken a wide turn near mid-ice, to send himself charging toward Fleury.
Ovechkin showed the puck on his forehand before deking to his left and lifting a backhand over Fleury's right pad with 1:23 remaining in the first.
In his past 14 games, Ovechkin has scored 14 goals, including three in two games against Pittsburgh. After scoring five points and three goals in his past two games, Ovechkin has 37 goals, two ahead of Rangers forward Rick Nash for the League lead.
Pittsburgh scored its first goal against Washington this season in the second period.
Letang held off a Capitals defenseman while controlling the puck through the offensive zone before one-handing it toward the Washington crease. Pittsburgh's Craig Adams and Washington's Jack Hillen converged on goalie Braden Holtby, knocking him into the net, and the puck slipped out of the crease to Steve Downie alone in front.
Downie roofed a wrist shot over Holtby to tie the game 3:35 into the second. The goal was Pittsburgh's first against Washington since Sidney Crosby scored with 5:48 remaining in the third period of the Penguins' 2-0 win on March 11, 2014.
Pittsburgh's power play has failed to score on its past 18 chances, including one that began with 2:07 remaining in the game.
"If you score one goal a game, you're not going to give yourself a great chance to win," Crosby said. "So we need to look in the mirror a bit. … It's good to get one, but like I said, you need to score more than that, and obviously, we had gotten zeros the first couple times, and to finally get one was nice, but it would've been better to build off it."