Their power play was powerless for much of the night, standing out like a sore appendage yet again in a game that was up for grabs.
But in the space of roughly 90 seconds of game time, spread out over the final ticks of regulation and the opening seconds of overtime, the Rangers powered up.
Two power-play goals, one to send Game 5 to overtime and another to win it, and the Rangers went from needing some of their mental toughness to rally from a 3-2 series deficit to needing one more win to reach their first Eastern Conference finals in 15 years.
It all happened with breaks, detail work and puck luck that often decide a series, one that finds stars such as Alex Ovechkin being congratulated for blocking a shot rather than scoring.
The Rangers "just stayed with it," John Tortorella said, and patience is one of the mantras he preaches. His team had a 26-10 edge in shots after two periods but mustered only one goal. Through 40 minutes, they had three power plays that produced a combined zero shots on net.
When John Carlson's blast clipped off Ryan Callahan and past Henrik Lundqvist early in the third, the Caps had a chance to win their third game of the series on a third-period power-play goal. That made the Rangers' power-play failures all the more pronounced.
John Mitchell said he felt the Rangers were doing well with the power play. When that was relayed to Tortorella, he said: "I'm not so sure about that. It's streaky, though."
And it's helped by winning faceoffs. Brad Richards, imported here with a championship pedigree and big-moment play, won two faceoffs in the final 30 seconds of regulation.
Off the first, the Caps' Joel Ward caught Carl Hagelin in the mouth with a high stick and drew blood, which made it a four-minute penalty.
Off the second, to start that power play and 21.3 seconds on the clock, the puck wheeled low to Callahan, who had two whacks stopped by Braden Holtby. Richards got the third whack and somehow smacked it past Holtby, through Carlson, off the far post and in.
"He was a monster for us," Brian Boyle said. "He's been a monster for us just about every night."
Less so has been Mitchell, one of the Rangers' fourth-line soldiers. He won a huge faceoff in OT, right back to Marc Staal. "I kind of got tied up with [Matt] Hendricks, too," Mitchell said, "and that gave Staalsie an extra second to line up a shot."
The shot ticked off Brooks Laich, maybe off Hendricks, too, and behind Holtby.
Two unlikely power plays. Three faceoff wins. One scramble goal to end all scramble goals for a tie. One double-deflected shot to win. Two power-play goals to grab a win when defeat seemed all but certain.
"That's when you stay with it," Richards said, showing why he's one of Tortorella's favorite pupils going back a decade to Tampa Bay. "You just battle through and learn from what you did earlier in the game."
The Rangers head south with a chance to win another series in which the difference between the teams is as small as a key faceoff win or an inadvertent stick to the mouth.
Thanks to a power play that went from powerless to powerful at the most crucial times.