Defenseman Mike Green scored on a power play, and Jose Theodore made 21 saves, helping Washington improve to 26-11-3, the best 40-game mark in franchise history. The Capitals are an Eastern Conference-leading 17-1-1 at home this season.
New York's Petr Prucha scored for the second game in a row.
The Southeast Division-leading Capitals have won 11 of 12 overall to move up to No. 2 in the East, and Ovechkin has 13 goals in that span. He entered Saturday second in the NHL in goals (26) and points (52).
Ovechkin added to those totals while teammate Matt Bradley was in the penalty box for a delay-of-game penalty that Capitals coach Bruce Boudreau protested vigorously.
Dave Steckel sent a short pass over to Ovechkin near center ice, and the player known as Alex the Great did the rest. Pressured by two Rangers, Ovechkin crossed the blue line and let fly a wrister across his body that snapped off the far post and by goalie Steve Valiquette, who was making only his ninth appearance this season.
The Rangers' No. 1 goalie, Henrik Lundqvist, did not start because he was "a little under the weather," coach Tom Renney said.
The goal was the league-worst 12th short-handed tally allowed this season by the Rangers; no other team had let in more than eight entering Saturday.
It also displayed the sort of individual excellence that prompted Boudreau to wonder before the game why his left wing finished sixth among Eastern Conference forwards in the final All-Star tally announced Saturday.
"It's dumb," Boudreau said, adding: "It's not right the best player in the game is not a starter."
Renney certainly knew what his team was up against. Asked before the game how he planned to deal with Ovechkin, New York's coach said with a laugh, "Kill him?"
Still, the Rangers did a good job of holding Ovechkin in check early, and the visitors went ahead 1-0 about 10 minutes into the second period. Brandon Dubinsky sent a pass to Prucha, who was alone at the top of the crease and simply redirected the puck past Theodore.
Less than 1½ minutes later, though, Green scored his 10th goal - eighth on a power play - off a pass from Alexander Semin to tie it. Semin, returning after six games out with a back injury, was ejected in the third period after fighting with Marc Staal.
Notes: The Capitals have won their past five games against the Rangers. ... In their previous meeting, at New York on Dec. 23, the Capitals trailed 4-0 before coming all the way back to win 5-4 in overtime, the start of Theodore's five-game winning streak. ... The capacity crowd of 18,277 was Washington's fifth consecutive sellout and ninth this season, more than all of last season. ... With Semin back in the lineup, the Capitals assigned Alexandre Giroux to Hershey (AHL). Giroux has one goal and one assist in 11 games with Washington this season.