Nicolas Aube-Kubel gave Washington a 2-1 lead at 11:15 with an unassisted goal, skating around Andrew Peeke in the left circle before scoring his first goal this season in his 19th game.
"I thought from about the 10-minute mark in the first period on, we did a really good job of pushing things," Capitals coach Peter Laviolette said. "I can't explain the second period. Guys are pushing; [we] seemed to turn it on a little bit as that game went on, seemed to keep pushing the whole way."
Gavin Bayreuther tied it 2-2 at 12:59 with a shot from the left side that went off Kuemper.
Martin Fehervary put Washington back in front 3-2 at 17:20 when Strome's shot hit Fehervary's helmet and floated over Merzlikins.
"The second period, I think the floodgates started to open a little bit and they've been going in, so I think we need to keep getting guys to the net and keep shooting the puck," Strome said. "Hockey's pretty fun when you score four, five, six, seven, nine in a game."