Capitals captain Alex Ovechkin had two goals and an assist to reach 500 career NHL points.
Boyd Gordon, Mike Knuble, and defenseman Tom Poti added goals for the Capitals.
New York returned home from a 1-2 Western trip, but couldn’t turn its best offensive output in eight games into a win. Vinny Prospal had two goals, and newly acquired forward Olli Jokinen, Brandon Dubinsky, and Ryan Callahan also put pucks past goalie Jose Theodore. The Rangers lost in regulation for the seventh time in eight games.
Leading scorer Marian Gaborik had two assists, as did Jokinen and Prospal for New York. But Jokinen was also called for three penalties, including a hooking call against Poti that led to Backstrom’s winning goal.
The Capitals, who lead the NHL in scoring, erased deficits of 1-0, 2-1, and 5-3.
The Rangers carried play in the first period and took a 1-0 lead at 8:58 when Callahan tipped in a shot in front by Jokinen, snapping New York’s 0-for-25 power-play slump over seven games. Gordon tied it with 3:20 left in the frame, despite Washington being outshot, 15-5, at the time.
Senators 3, Canucks 1 - Jason Spezza scored his ninth goal in his last eight games and host Ottawa extended its team-record winning streak to 11.
Brian Elliott made 29 saves to break his own team record with his ninth straight win. He lost a shutout bid when Kyle Wellwood scored a power-play goal with 1:39 left.
Sharks 4, Blues 2 - Patrick Marleau scored his 38th goal to remain tied for the NHL lead, helping Western Conference-leading San Jose in St. Louis.
Ryane Clowe and Devin Setoguchi also scored, and backup Thomas Greiss had a strong game in goal for the Sharks, who rebounded from their lone regulation loss in the last 11 games after squandering a two-goal lead against Detroit two days earlier.
Kings 6, Ducks 4 - Dustin Brown scored the go-ahead goal with 5:32 left after host Los Angeles blew a three-goal lead in the third period and the Kings tied a franchise record with their eighth straight victory, beating Anaheim.
Anze Kopitar had two goals and two assists, defenseman Jack Johnson had a goal and three assists for his first four-point game in the NHL, and Jonathan Quick made 18 saves to help the Kings beat their rivals for the fifth straight time.
