Tom Wilson had a goal and an assist, and Dylan Strome and Aliaksei Protas scored for the Capitals (21-15-5), who have lost five of their past seven games (2-4-1). Thompson made 28 saves.
"No excuses, we fell apart in the second and the third," Thompson said. "That's what happens when you let good teams kind of hang around; they have a lot of fire power."
Wilson gave Washington a 1-0 lead at 8:13 of the first period. Merilainen made three saves in a span of three seconds before Wilson finished on a rebound. It was Wilson's fifth goal in three games.
"It seems like right now we're finding ways to lose games," Strome said. "That's kind of something that we've got to fix and correct. You never want to be out there for goals against; you don't want to feel like you're hurting your team. I feel like, for whatever reason right now, we're kind of getting caught on the wrong side of pucks and it seems like every time they're going in the net."
Strome made it 2-0 with a power-play goal at 18:59. He skated in from the point and beat a screened Merilainen glove side with a wrist shot.
"Probably can't repeat a lot of the things that I said," Green said of addressing his players in the first intermission. "I just didn't think we were into the game. I just thought we weren't playing to win. We were playing light, there wasn't a lot of firmness, heaviness to our game. We were on the outside looking in, and that's really uncharacteristic of our team when we're playing well, especially under the circumstances of our last few games. But I give them a lot of credit; they showed a lot character to turn the page and come out and play with a lot of energy, a lot of compete."
Jensen cut it to 2-1 at 7:42 of the second period. Moments after Jake Sanderson hit the cross bar, Jensen's shot from the right side beat Thompson before he could reset.