Seven seconds until overtime Thursday night, until the green light flickered, the third period ended and Game 1 of the Eastern Conference semifinals moved to sudden death. The puck sat in the corner, pinned against New York Rangers defenseman Dan Boyle’s skate, waiting for the final horn to blare. Six seconds. Washington Capitals center Nicklas Backstrom bolted ahead, hunting for one last check, one last prayer.

Five seconds. Backstrom crunched Boyle and jostled the puck free. Four seconds. Forward Alex Ovechkin grabbed possession and tore around the net, three blue sweaters eying his move, anticipating a wraparound. Three seconds. Through the clamor of Madison Square Garden, Ovechkin heard his screaming teammate. Two seconds. He fired a no-look pass, across his body and toward the crease. Somehow, everyone had forgotten about Joel Ward.

“You just play toward the end,” Ward said. “I think you teach that in [youth] hockey. I didn’t even know there was time left. It was so loud. . . . When I saw that [puck], my eyes did light up a little bit.”

The chaos that followed, from the Rangers howling that Backstrom had boarded Boyle to the confusion over whether Ward’s blast had even beaten the buzzer, turned into a mad celebration for the Capitals, who with 1.3 seconds left snatched a 2-1 victory and the series lead. Ovechkin sprinted toward the bench, kicking up ice with every step. Ward welcomed his teammates and hollered, even louder than when he summoned the game-winning feed.

Behind them, Rangers goaltender Henrik Lundqvist hunched over, stunned. It was just the third time in Stanley Cup playoff history a game-winning goal had come inside the final two seconds of the third period.

Post Sports Live debates the Capitals' ceiling in the NHL playoffs coming off of a Game 7 win over the New York Islanders. (Post Sports Live/The Washington Post)

The crowd, once delirious after Jesper Fast notched the tying goal with less than five minutes left in the third period, hushed. The Presidents’ Trophy winners had fallen for only the second time in these 2015 playoffs, and the Capitals had secured a series-opening win on the road for the first time since 2003. It took a moment for reality to dawn. Even later, it still hadn’t quite settled.

“We were just high-fiving, dancing, whatever,” Ward said. “I didn’t know until we all looked up. I didn’t know at the time. We were just celebrating at that moment.”

“The whole building and everyone on the ice was expecting overtime,” Backstrom said. “But you’ve got to battle hard until the whistle goes.”

“I get lucky,” Ovechkin said. “It was kind of hard angle, but sometimes luck step on our side.”

Fortune would suffice for now, once the elation subsided and the Capitals parsed through the effort that pulled home-ice advantage into their corner. They had ridden Ovechkin’s first-period howitzer, a laser beam rifled on the rush, which slammed out of the net with such force that only Ovechkin realized it had beaten Lundqvist. Their shorthanded unit had squelched two more power plays, staying perfect through 16 tries in the postseason. They had countered the Rangers’ speed with physical might, much like the playbill suggested, and received 31 saves from goaltender Braden Holtby, who narrowly missed recording his second career postseason shutout.

They would gladly accept the miracle, return to their hotel and prepare for Saturday afternoon’s Game 2.

“I didn’t think we played very good today,” Coach Barry Trotz said. “I know we’ve got another level in our game.”

Bucket drummer Bernard Aljaleel, homeless for five years, plays for fans after most home games. With the Capitals and Wizards advancing in the playoffs, it will give him the chance to make some extra cash. (McKenna Ewen/The Washington Post)

Trotz could not say the same about his captain. Inside the 18-minute mark, with New York forward Dominic Moore dispatched for holding, Ovechkin tore down the left side and bore down upon Boyle, who skated backward and crouched low to block a shot. As Boyle straightened up, Ovechkin dragged the puck behind his body, cocked back and launched to the inside. The move turned Boyle into an unintentional screen for Lundqvist, who entered with two consecutive playoff shutouts of the Capitals, both during the first round in 2013.

As the puck sailed over Lundqvist’s blocker pad and Ovechkin began celebrating, the whole building hushed and watched the replay. As the result became clear — Ovechkin’s third goal of the postseason, first on the power play, and a 1-0 advantage for Washington — murmurs rippled through the stands. Did Lundqvist even see the puck? For that matter, had anyone?

“All series, baby,” Ovechkin screamed at Lundqvist, caught on the rink microphones. “All series.”

The second period passed with the Capitals’ lead still intact, though not for lack of bodies flung onto Holtby’s doorstep, trying to wreak havoc in the crease. Both he and Lundqvist held strong against opposing attacks, snagging wrist shots with their gloves and clearing loose pucks with their sticks. Fifteen minutes elapsed in the third period too, the Rangers unable to capitalize off three straight icings and Ward buzzing a point-blank attempt off the post.

Then the Rangers began their most dominant shift of the night, hemming the Capitals inside their zone, cycling pucks and pestering Holtby until the puck flopped to forward Kevin Hayes at the point. It seemed all but inevitable by the time Hayes aimed into traffic, where Fast earned credit for the deflection. Holtby propped himself onto one knee and stared straight ahead, while the white towels waved and the Rangers celebrated their tying goal. Overtime was coming.

So the clock ticked away. Less than 10 seconds remained when Rangers converged onto Ovechkin, who steamed beyond the blue line, lost control and tumbled onto the ice. The puck scooted into the corner. Boyle gained control and waited. Ward circled into the slot and did the same. Then he started screaming.

“I just took a hard whack at it,” Ward said. “I didn’t even know what was going on. I just took a whack at it, went in, and sure enough beat the clock.”