WASHINGTON -- In the span of four days, the New York Islanders may have turned their season around.

Jaroslav Halak made 38 saves for his first shutout of the season and the Islanders scored three third-period goals to defeat the Washington Capitals 3-0 on Thursday night at Verizon Center for their third straight victory after beginning the week with only six wins.

Shane Prince, Brock Nelson and former Capital Jason Chimera scored in a 4:28 span for New York (9-10-4), which owns its first three-game winning streak of the season. New York topped the Flames on Monday and the Penguins on Tuesday.

"To be able to string three in a row together -- especially with back-to-back against two of the best teams in the league -- is huge for us," Prince said. "We've got to build off it and keep it going."

Halak picked up his 40th career shutout, blanking the Capitals despite six Washington power plays.

"Story of the game, our power play wasn't very good. They're penalty kill won them the game," Washington's Matt Niskanen said. "Five-on-five we probably played well enough to be in the game, which we were, but you get that many chances on the power play, you should win the game."

Alex Ovechkin nearly gave Washington a 1-0 lead when he hit the post on a power play attempt early in the third period. Ninety seconds later, Washington's Dmitry Orlov turned the puck over. Prince skated into a pass from Casey Cizikas in the neutral, broke in alone and wristed a shot past Braden Holtby at 3:15 of the period.

The Islanders made it 2-0 at the 6:43 mark after another Orlov turnover led to a scrum in front of the net. Nelson fired a loose puck through a crowd for his sixth of the season.

"I (made) two bad mistakes and it lost us the game," Orlov said.

It was 3-0 after Chimera lifted a back-hander over Holtby's shoulder at 7:43.

"To be going into the third period 0-0 in a tie game, it's exactly what we want," Prince said. "We wanted to go out there and steal that one and kind of get the train rolling here."

Against Pittsburgh, the Islanders surrendered a 3-0 third-period lead, but scored twice in the final minute.

"Just a great effort back-to-back nights against two great hockey teams," Islanders coach Jack Capuano said after last-place New York beat the second-place Penguins and a Washington team tied for third in the Metropolitan Division.

Holtby made 25 stops for Washington (13-7-2), which had been off since losing Saturday.

"Three goals in that span, it can't happen," Holtby said. "No matter what they are. Third goal especially."

Washington had the better chances over the first 20 minutes.

Halak made a pad save to stop Tom Wilson on a breakaway attempt early. Then, during a Washington power play, he denied Justin Williams from the slot and Ovechkin fanned on an open net attempt in close.

"He made some big save when he had to," Capuano said of Halak, "especially Williams on the power play."

The Capitals appeared to take a 1-0 lead on a power-play goal as the first period expired. Williams deflected a feed past Halak that was ruled a goal on the ice. A replay review showed, however, that the puck had not yet crossed the goal line when time ran out.

"I did," Capitals coach Barry Trotz said when asked if he originally thought it was a goal, "and then obviously the monitors and all that ... that's why you have them. In the old days that would have been a big goal."

Halak kept the game scoreless when he made a sliding stop on Lars Eller on the doorstep midway through the second period.

Now after weeks of bad bounces and poor play late in games put them in a hole, the Islanders are digging themselves out.

"Obviously still some things to clean up, but we're heading in the right direction," Halak said.

NOTES: LW Jakub Vrana, 20, Washington's first round pick (13th overall) in the 2014 NHL Draft, made his NHL debut and skated on a line with RW Andre Burakovsky and C Evgeny Kuznetsov. ... D Matt Niskanen, who left Washington's previous game with a lower-body injury, was in the lineup. ... The Islanders lead the league in blocked shots. ... The Capitals scratched D Taylor Chorney and C Paul Carey. ... Islanders D Dennis Seidenberg, who missed six games with an upper-body injury, was activated and D Adam Pelech (upper body) was placed on injured reserve. LW Anthony Beauvillier, D Scott Mayfield and G Thomas Greiss were the New York scratches.