WASHINGTON -- The Washington Capitals didn't look like their recent selves early on against the Philadelphia Flyers.

By the end of the game, however, the NHL's hottest team had turned in another dominant performance.

Justin Williams and Matt Niskanen each scored twice within a five-minute span of the third period, Philipp Grubauer stopped 24 shots and the Capitals defeated the Flyers 5-0 on Sunday at Verizon Center for their ninth straight win.

"Either they were buzzing or we were a step slow. Could have been both," Niskanen said of the scoreless first period. "But (Grubauer) was outstanding, especially in the first. Gave us a chance to find our legs. We got better as the game went on and we were real good in the third."

The Capitals managed just 10 shots in two periods and led 1-0 before the Williams-Niskanen outburst.

Washington (29-9-5), the defending Presidents' Trophy winner, moved ahead of idle Columbus for first place in the Metropolitan Division as well as for the overall NHL points lead.

The Capitals have not allowed an even-strength goal since Jan. 3 against Toronto, a span of 369:14.

With Braden Holtby being rested ahead of Monday night's game at Pittsburgh, Grubauer stopped an early Flyers surge and picked up his second career shutout.

"Everybody seems to be doing their job at a high level right now, and that's why we're being successful," Williams said.

Andre Burakovsky scored the first goal and Nicklas Backstrom had two assists for the Capitals, who have outscored opponents 40-11 in the last nine games.

"We haven't talked about it a ton. It's been fun, though," Niskanen said of the winning streak. "I think guys are enjoying coming to the rink right now."

Flyers goalie Steve Mason (12 saves) was lifted after Williams made it 5-0 with 13:24 left in the game.

Philadelphia (22-18-6) fell to 3-8-3 in its last 14 games. The Flyers went 0 of 5 on the power play.

"Earlier this year when things went wrong, we fought through. Right now, the negative energy is a landslide," Flyers coach Dave Hakstol said.

The Flyers outshot the Capitals 13-5 in the first period but were unable to cash in. Grubauer was solid, especially early when he stopped Mark Streit in front and then Dan Weise on the rebound attempt.

"Obviously, it helps seeing the puck there in the first couple of seconds, get into the game," Grubauer said. "It's been awhile since I played."

Washington led 1-0 thanks to a power-play goal at 9:08 of the second period. Flyers defenseman Michael Del Zotto flubbed a clearing attempt and Burakovsky corralled the puck and fired high past Mason from the slot for his sixth goal.

"It hopped over my stick, right on the guy's tape coming right down Broadway," Del Zotto said. "An unfortunate bounce, it seems the way things are going right now."

Philadelphia came close to tying the score twice.

First, Radko Gudas' high shot from beyond the blue line fooled Grubauer and went in, but the play was whistled offside. Then, with the Flyers on a power play later in the period, Streit hit the post.

The Capitals put it away early in the third period thanks to a couple of highlight reel passing plays.

Marcus Johansson helped make it 2-0 at 1:36 of the period when he started behind Mason and then sent a perfect backhand pass in front to Williams, who roofed it.

"A very winnable game for us," Del Zotto said. "We get into the third period, give up that second goal, then the floodgates opened. Just kind of collapsed after that."

Less than two minutes later, Backstrom entered the zone two-on-one with Alex Ovechkin. Ovechkin took the feed in the left circle, but rather than shoot as Mason slid across, Ovechkin centered the puck to a streaking Niskanen, who fired into a wide-open net.

Niskanen, who entered the day with two goals all season, made it 4-0 when his blast from the right pointed deflected off Mason's glove and in.

Williams completed the outburst at 6:36 when he scored in front off a feed from Backstrom for his 14th goal of the season.

That ended Mason's day as former Capitals goalie Michael Neuvirth finished.

NOTES: Washington, which notched its 1,500th franchise win, played the final two periods without defenseman John Carlson, who left with a lower-body injury. ... Before the game, the Capitals held a ceremony honoring C Nicklas Backstrom, who recently collected his 500th career assist, becoming the first Washington player to do so. ... D Taylor Chorney and C Chandler Stephenson, who was recalled Saturday from Hershey, were the Washington scratches. ... D Shayne Gostisbehere, a healthy scratch Saturday against the Bruins, was back in the Philadelphia lineup. ... The Flyers scratched D Brandon Manning, D Nick Schultz and RW Matt Read. ... The Flyers begin their bye week after Sunday's game and are off until they host the Devils on Saturday.