WASHINGTON -- Fighting for a playoff spot, the New York Islanders could ill afford to waste a two-goal lead to start a crucial four-game trip.
New York built a two-goal lead in the first period only to see Washington score twice in the second.
The winner came after Matt Moulson forced a turnover next to the Capitals' net and fed Tavares in the right circle for his 20th goal of the season. Michael Grabner and Josh Bailey also scored for the Islanders.
"It was a real super forecheck. We were starting a line change and decided to stay out there," Tavares said about his goal. "(Mike) Green fumbled it there. Matt got his stick on it and made a good play, got it to me. I used their forward there as a screen and just got a lot on it."
Washington's Brooks Laich had sent the puck around the back of the net to Green and as Green was trying to play the puck, Moulson arrived and took it away.
"Not a good interchange between (Laich) and (Green)," Capitals coach Adam Oates said. "Brooks was tired so he just wanted to bank it to him and it was obviously bouncing. A play I'm sure those two guys would like back. A tough play for Greenie."
Green was not made available afterward and Laich took responsibility for the play.
"I got caught out, a little fatigued, went back and I wanted to send it back behind the net," Laich said. "I didn't think I could get Mike direct. I didn't want to turn one over in the middle in front of our net so I sent it behind the net. Bad angle, bad decision by myself. I put Mike in trouble and it resulted in the winning goal."
New York (15-15-3) and Washington (15-17-1) are battling for playoff spots in the Eastern Conference. The Islanders have won two straight and improved to 9-4-1 on the road. They also ended Washington's winning streak at three games.
"Hopefully, our guys can build off this," Capuano said. "We came into a tough building with a great team and a good crowd and we came out of here with two points."
Tavares' line struggled through the first two periods.
"We met after the second and we knew they were going to find a way," Capuano said. "When you need a big goal it's that line that usually comes up for us, so it was good to see those guys respond in the third."
New York's Evgeni Nabokov made 20 saves to improve to 12-1-2 lifetime against Washington.
Braden Holtby stopped 28 shots for Washington.
"We had some surges where we played well and we didn't give (the Capitals) a whole lot in the second half of that second period, and then we came out in the third and they had the momentum," Islanders forward Kyle Okposo said. "They came at us, but at the end of the day we found a way to win."
With the Islanders already leading 2-0 in the second, Holtby made several good stops during a New York power play.
Ribeiro then cut the deficit in half at the 10:05 mark. Troy Brouwer led a rush into the Islanders' zone and dropped it to Ribeiro, who eluded a defender and beat Nabokov from the right circle. It was Ribeiro's 11th goal and team-leading 35th point.
Carlson tied it less than 3 minutes later on a slap shot from the right point with assists from Marcus Johannsson and Ovechkin.
Grabner opened the scoring at 5:24 of the first period. Keith Aucoin picked up a loose puck along the boards and passed to in front to a wide-open Grabner, who one-timed the puck past Holtby on the glove side for his 11th goal of the season.
New York made 2-0 minutes later on a similar goal. This time, Bailey took a crossing pass from Okposo in the right circle and one-timed it past Holtby on the stick side.
"I don't think we came out with the fire we needed, the intensity we needed," Washington's Matt Hendricks said.
Washington had several good chances later in the period. The Capitals kept the puck in the Islanders' end for several minutes during one stretch, but came away empty after Johansson hit the post. In the final minute of the period, Laich came in on a semi-breakaway during a New York line change, but Nabokov stopped his slapper.
Moulson's assist was the 100th of his career. . Ovechkin extended his points streak to six games. . After the home game Tuesday following a four straight on the road, Washington travels to Buffalo on Saturday. ... The Islanders four- game trip continues Thursday in Philadelphia.