Evgeny Kuznetsov beats Avalanche goaltender Semyon Varlamov for the winning goal in overtime. (John McDonnell/The Washington Post)

Washington Capitals center Evgeny Kuznetsov emerged from the dressing room just in time for overtime Thursday night, having passed the concussion protocol after taking a high hit in the third period. He started the extra frame, and then he ended it, sprung for a breakaway and making it count with 48 seconds left to lift the Capitals to a 4-3 win over the Colorado Avalanche.

“My job is to play hockey. Doctor’s job is to save my life, right?” Kuznetsov said.

In a game that featured porous goaltending on both sides, Washington’s Pheonix Copley got the win with a 34-save performance, and the Capitals have their first two-game winning streak in a month and are in sole possession of second place in the Metropolitan Division.

Washington took a 3-1 lead less than a minute into the third period, when Jakub Vrana’s shot hit Colorado goaltender Semyon Varlamov in the face mask and the rebound went to defenseman Matt Niskanen. Niskanen fired from beyond the faceoff circle, and while Varlamov got a piece of the puck with his blocker, it wasn’t enough to keep it out of the net.

But then Mikko Rantanen, one of the league’s top scorers, cut into Washington’s deficit less than five minutes later. The goal that really hurt came with 2:07 left in the third period, a bad-angle shot from Colin Wilson that Copley didn’t seem to expect. As he straightened in net, the puck slipped past his legs, a mistake that tied the score and led to overtime.

“I think that’s very stoppable,” Copley said. “I’ve got to make that save. . . . He kind of caught me when I was transitioning, so I was kind of in an awkward position. But, still, you’ve got to make that save.”

Thursday’s game at Capital One Arena marked Copley’s first start since he and the Capitals agreed to a three-year, $3.3 million contract extension Monday, a commitment the team made based on just 21 NHL appearances, all but two of which came in the first 53 games of this season. He hadn’t started a game in more than three weeks, and he recorded a loss in his previous four outings. Copley had mostly good moments Thursday, stopping 32 shots through regulation, but he also allowed two bad goals — Wilson’s and one from Colorado star center Nathan MacKinnon in the second period.

“I think that for the most part we did some decent things in the third to protect the lead, and obviously that’s probably one that Pheonix would like to have back,” Coach Todd Reirden said. “But that’s the team — it’s a team game — and I loved how our team rallied behind it, knowing just that that’s the way it goes.”

The Capitals were able to take advantage of Varlamov’s shaky rebound control. Promoted to the third line for this game, winger Andre Burakovsky scored the first goal of the game, his seventh of the season, 6:31 into the first period by redirecting T.J. Oshie’s feed at the front of the net. Washington appeared to extend its lead 14:51 into the game after Alex Ovechkin’s slap shot on the power play was initially stopped by Varlamov. The puck squirted out from between Varlamov’s pads, and center Nicklas Backstrom smacked it into the net.

However, a video review determined the referee had already blown the play dead before the puck crossed the goal line, so the call was reversed. It was a significant break for the Avalanche, which has the league’s worst save percentage over the past 25 games. After Philipp Grubauer had a career year with the Capitals last season — he played in 35 games and compiled a .923 save percentage and 2.35 goals against average — he requested a trade to somewhere he could have the opportunity to ascend to the top role, which wouldn’t be possible with Braden Holtby entrenched in goal in Washington.

The Capitals obliged, dealing him to Colorado, where he has shared the net with Varlamov, also a former Washington netminder. Grubauer didn’t play Thursday, but for his first trip to Washington in another jersey, the team showed a tribute video for him, which he acknowledged with waves from the bench.

The Avalanche had lost four straight entering this game, and the team is just outside a wild-card spot in the Western Conference standings, so the Capitals expected to see some desperation. Just 35 seconds into the second period, Tyson Barrie’s shot off the end boards rebounded right to MacKinnon, and as Copley scrambled back into position, MacKinnon managed to sneak the puck through a hole between Copley and the post.

Washington challenged that the play was offside, but the video review went against the Capitals again, which put them on the penalty kill for delay of game. After the early whistle in the first period, the home crowd was especially irked with the officiating.

“Things are going to happen that don’t go your way,” Reirden said. “There was more than one tonight that didn’t go our way. But we stayed with our game plan. Frustration was at a very low level on our bench. And that’s what top teams do — you find ways to get points when things aren’t going our way.”

In a near-identical play to that first-period power-play goal that was waved off, Ovechkin’s one-timer got through Varlamov, sliding toward the goal line before Kuznetsov gave it an extra shove across for a 2-1 lead 8:38 into the second period. The recent break has suited him; in the four games since Washington returned from its bye week, Kuznetsov has scored three goals among seven points, including Thursday night’s winner.

“His speed seems re-energized, refocused, and he’s been a major factor in these games,” Reirden said. “When he’s playing like that, he’s a huge asset to our team. You see the success we can have.”