Travis Boyd and Evgeny Kuznetsov also scored for Washington. Braden Holtby had 24 saves.
Ryan Getzlaf and Adam Henrique scored for Anaheim. Ryan Miller had 33 saves.
The game comes 2 1/2 weeks after the Capitals’ Garnet Hathaway was given a three-game suspension for spitting on the Ducks’ Erik Gudbranson after the players paired off late in Washington’s 5-2 home victory.
Gudbranson and Hathaway squared off twice Friday, with the first confrontation in the second period stopped immediately by referees. They matched up again with 16:54 remaining in the game, with Gudbranson dragging Hathaway to the ice before referees intervened.
The second confrontation between Gudbranson and Hathaway came shortly after Vrana put the Capitals ahead for good, giving Washington its sixth consecutive victory and eighth in 10 games.
The Capitals went 4-0 on a road trip that started in Detroit and included three stops in California.
The game also included a fight between the Ducks’ Nicolas Deslauriers and the Capitals’ Radko Gudas that stemmed from Gudas’ hit in the first period that knocked Nick Ritchie from the game with a left leg injury.
The Capitals jumped out to a 2-0 lead on a goal from Boyd at 9:00 of the first period, his second of the season, and another from Kuznetsov at 5:10 of the second period, his 12th. The Ducks began their comeback when Getzlaf picked up a loose puck in the slot and scored past Holtby.
Just 45 seconds into the third period the Ducks tied the score 2-2 on a goal from Henrique off an assist from Getzlaf.
It took less than a minute for the Capitals to regain the lead when Vrana scored his 15th of the season after first shooting on Miller and then scoring on the rebound.
NOTES: Ducks goalie John Gibson was a scratch after missing a day of practice this week with an undisclosed illness. … The Ducks entered with three consecutive home victories over the Capitals, one shy of their club-best four consecutive against Washington between 1996 and 1999. … The Capitals’ Alex Ovechkin remained one power-play goal away from tying former Ducks standout Teemu Selanne for third most all-time at 255, and seven goals from away from Selanne, who is 11th all-time at 684. … The Capitals have won eight of their last 12 games against the Ducks and lead the all-time series 19-18-1-1.
Capitals: Washington will return home from its four-game trip to face the Columbus Blue Jackets on Monday.
Ducks: Anaheim will hit the road to start a two-game trip Sunday at Winnipeg.