Nathan Walker scored two goals, and Jordan Binnington made 21 saves for the Blues (21-20-2), who have lost three straight (0-2-1).
St. Louis went 0-for-5 on the power play; Washington was 2-for-4.
“Power play, as a whole, they have to be better,” Blues coach Drew Bannister said. “We have to execute. That’s plain and simple and it bled into the rest of our game. It didn’t give us any momentum at any time.”
Oshie gave the Capitals a 1-0 lead on the power play at 10:24 of the first period when he controlled a contested puck in the left face-off circle and scored on a wrist shot over Binnington’s left shoulder.
“He’s a special player, a special guy to have in the room,” Strome said of Oshie. “I think you can tell the way our team plays when he’s in the lineup and when he’s not. I think he adds a ton to our team and in the dressing room as well.”
Walker tied it 1-1 at 17:54, scoring on a deflection of Nick Leddy’s shot from the left point.
Nicolas Aube-Kubel gave Washington a 2-1 lead at 3:32 of the second period when his centering pass deflected in off St. Louis defenseman Justin Faulk in the slot.
“I think it actually bounced up off the ice and hit me in, like, the ankle,” Faulk said. “I thought it was going to stay on the ice, and that's an easy handle. But, yeah, obviously I'm not trying to redirect it. I was just trying to get it to stop in my feet and make the play out and it just ricocheted off pretty good.”