Ryan Nugent-Hopkins had a goal and an assist, Tobias Rieder had two assists and Cam Talbot made 31 saves for the Oilers (4-3-1), who are 4-1-1 in their past six games.
"It definitely is a confidence boost," Nugent-Hopkins said. "Just the way we played tonight, it didn't matter who we played, we played a solid 60 minutes and didn't give up too many Grade-A opportunities, or give up the puck too much. And when we had our chances, we capitalized. To keep a team like that to one goal is a good sign for our club."
Nugent-Hopkins made it 2-0 at 10:06 of the second period with Edmonton's first shorthanded goal of the season. After intercepting a back pass from Capitals defenseman John Carlson at the Washington blue line, he skated around Nicklas Backstrom before beating Holtby blocker side from the right circle.
"That was just a bad play, really," Carlson said. "I really didn't have to go direct in that situation, I had plenty of other options to do, and just made a bad play."