Carl Hagelin used his speed to chase down a dump-in in the lower right corner of the Capitals' zone and curled behind the net with the puck on his backhand. As he came out the other side, Hagelin feathered a pass up to Richards, who one-timed a shot that beat Holtby inside the right post while Gaborik was in front of the net.
It was Richards' team-leading fourth goal of the series and sixth of the playoffs.
"It's a big goal. It gets the nerves out," Richards said. "You don't exhale, but you have the 1-0 lead. You got the crowd in it. They're not waiting for something to happen.
"They did it to us in Game 6 when they got an early goal. We did that tonight."
Although Washington controlled the puck for large chunks of the game, the Capitals yet again couldn't overcome the dreaded 1-0 deficit. The team that scored first won all seven games in the series. The numbers were even more stark for the Capitals, who went 0-6 in the playoffs after allowing the first goal and 7-1 when they grabbed the first lead.
Del Zotto started and finished the Rangers' second scoring play. He leveled Capitals captain Alex Ovechkin in the New York and moved the puck up ice. He eventually took a pass from Gaborik and snapped a shot past Holtby.
However, before the cheers subsided, the Capitals got back within a goal on Hamrlik's first of the playoffs.
This one was tight throughout.
Washington was outshot 12-11 in the second period, that featured a blank score sheet with no goals and no penalties. Midway through the frame, the Capitals kept the pressure on the Rangers with Ovechkin's line on the ice and camped out in the New York end for about two minutes.
As the tired Rangers chased Washington all around their zone and unable to change any players, the Capitals moved the puck side to side and up and down, seemingly keeping Lundqvist on a swivel. Many of their shots were offline, but the Capitals produced several prime chances that Lundqvist turned away - each one drawing sighs, but appreciative cheers from the towel-waving crowd.
"We came up short. We played a good team and a great goalie," Capitals forward Nicklas Backstrom said. "The Rangers played the way we played last game. They got a lead at the beginning and they controlled the game. We had some good puck possession in the second period but we couldn't get any real opportunities."
Mike Knuble had a good whack at the puck at the left post, but Lundqvist was there with his pad to keep it out.
Holtby, who became a father on Thursday, shook off Richards' early strike and seemed to gain confidence as the game wore on and the pressure built at the other end of the ice.
Notes: Richards, who improved to 4-0 in Game 7s, has recorded a goal and three assists in those games. He has seven goals and eight assists in the last 11 games in which his team has faced elimination. ... Hagelin, who had two assists, had his first points in 10 games, dating to an assist in New York's playoff opener against Ottawa. ... Injured Capitals forward Jay Beagle missed his second straight game, and Jeff Halpern took his place again. ... Fedotenko improved to 6-0 in Game 7.
PHT: The Bruins try to complete their sweep tonight (7 p.m. ET; Live Extra, CNBC). On NBCSN, the Hawks and Wings play (7 ET; Live Extra), then the Sharks and Kings square off (10:30 ET; Live Extra).
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