Anthony Mantha had a goal and an assist, and Darcy Kuemper made 31 saves for the Capitals (10-11-3), who ended a six-game road losing streak.
Washington, which has won three of its past four games overall, got goals from three lines.
"That was a good 60 right there," Mantha said. "We were hard on them, obviously made good O-zone plays and the puck bounced our way."
Spencer Martin made 23 saves for the Canucks (9-11-3), who had a season-long three-game winning streak end.
"We feel like we've come together and we're getting better and better and building, so to come here and have a game go that way is disappointing," said Martin, who started for the third time in four games. "And I take a lot of responsibility for this loss because the goalie has a unique way to affect the game and I felt like early in the game, I didn't do enough to give us a chance."
Ovechkin set the tone early for the Capitals, who did not lead at any point in their four previous road losses.
"He was really good in the first and I thought we were really good in the first so it was nice to get out and get a jump like that," coach Peter Laviolette said. "He certainly led. We knew we needed to have a good first period, have a good game and you need your best players to do that."