Just under six minutes after Ryan Callahan got the Rangers even with a power-play goal, Ovechkin put the Capitals ahead for good after they squandered a 2-0 lead.
Mike Knuble and Jason Chimera scored first-period goals for the Capitals, who will host the next two games of the series. Washington is trying to repeat its first-round feat when it lost the series opener but rallied to beat Boston in seven games. The Capitals have earned four of their five wins in this post-season on the road.
Brad Richards had a goal and assist, and defenceman Michael Del Zotto had two assists for the top-seeded Rangers, who got forward Brian Boyle back from a three-game injury absence but couldn't turn it into a commanding lead in the series.
KINGS 5, BLUES 2
ST. LOUIS (AP) — Anze Kopitar scored twice in a four-goal, first-period blitz and Los Angeles embarrassed the Blues from the opening faceoff, whipping St. Louis for its fifth straight road win this post-season.
Mike Richards and Jeff Carter had a goal apiece and Dustin Penner and Dustin Brown each had a pair of assists in a period that was one goal shy of the franchise playoff record of five in 1993 against Vancouver.
Brown assisted on Kopitar's short-handed goal and has a hand in all four of the Kings' short-handed goals in the playoffs, two goals and two assists.
Andy McDonald scored 18 seconds into the second for St. Louis but Justin Williams squashed thoughts of a comeback when he scored on the Kings' first shot of the period, then they sat on that cushion, taking five shots the last two periods.
Matt D'Agostini scored in the third for St. Louis, which was 0 for 9 on the power play.