PITTSBURGH -- Kevin Shattenkirk knew he could improve and showed it Monday.
Shattenkirk scored a power-play goal 3:13 into overtime to give the Washington Capitals a 3-2 win against the Pittsburgh Penguins in Game 3 of the Eastern Conference Second Round at PPG Paints Arena.
After Trevor Daley was called for holding Marcus Johansson at 2:40 of overtime, Shattenkirk beat Marc-Andre Fleury with a wrist shot from below the circles for his first goal of the Stanley Cup Playoffs.
[WATCH: All Capitals vs. Penguins highlights | RELATED: Complete Washington vs. Pittsburgh series coverage]
The Penguins lead the best-of-7 series, 2-1. Game 4 is here on Wednesday (7:30 p.m. ET; NBCSN, CBC, TVA Sports).
Pittsburgh played most of the game without center Sidney Crosby.
Crosby left the game 5:24 into the first period after he charged toward the net on a 2-on-1. Alex Ovechkin hit him with his stick, which seemed to make Crosby stumble before Matt Niskanen cross-checked him in the side of his head.
Trainers helped Crosby to the locker room after he was face down along the goal line for a few minutes. Niskanen was given a major penalty and game misconduct for cross-checking.
Penguins coach Mike Sullivan did not update Crosby's condition following the game. He said Crosby and Conor Sheary, who left with an apparent injury after colliding with linemate Patric Hornqvist at 2:24 of the second period, would be evaluated overnight.
Sullivan said the approach would not change if Crosby were unable to play moving forward.
"We're hopeful, first of all, that that won't be the case," Sullivan said. "But I think this group has so much character and talent that we're able to endure the injuries that we have. We've done it all year long. We continued to do it tonight, and we'll continue to do it."
Video: WSH@PIT, Gm3: Crosby exits with injury early in 1st
After the morning skate, Shattenkirk expressed frustration with his performance in a 6-2 loss in Game 2 on Saturday, when Matt Cullen beat him on a shorthanded goal. His tune has since changed.
"I think tonight was a great test for all of us," Shattenkirk said. "There were a lot of different moments in the game where we had to see what we were made of. For me, it was a shift-by-shift process. Obviously, I feel a lot different than where I was standing 12 hours ago with you guys, but I have to make sure I carry this into the next game."
Pittsburgh rallied to force overtime on goals by Evgeni Malkin and Justin Schultz 48 seconds apart late in the third period.
Evgeny Kuznetsov gave the Capitals a 2-0 lead at 9:46 of the third period, but Malkin cut it to 2-1 with Fleury pulled for an extra attacker with 1:53 remaining.
Video: WSH@PIT, Gm3: Malkin hammers one-timer by Holtby
Schultz tied it when his slap shot got past Braden Holtby with 1:05 left.
Backstrom scored the Capitals' first goal during a 5-on-3 at 13:05 of the first period.
Chris Kunitz appeared to tie it 1-1 at 1:05 of the second period when a backhanded pass from Malkin went off him while he crashed the crease.
The goal was upheld after an initial review, where it was ruled the puck crossed the line before the net came completely off its moorings. But it was disallowed after the Capitals successfully challenged for goaltender interference.
Holtby made 28 saves. Fleury stopped 30 shots.
Video: WSH@PIT, Gm3: Kuznetsov finishes slick passing play
Goal of the game
Backstrom passed back to Shattenkirk, setting him up for the overtime winner. T.J. Oshie skated in front of Brian Dumoulin, which caused a screen in front of Fleury. Oshie jumped out of the way of Shattenkirk's shot to allow it to sneak under Fleury's blocker.
Video: WSH@PIT, Gm3: Shattenkirk nets PPG for OT win
Save of the game
Fleury kept the Capitals from extending their lead to 2-0 late in the second period after stopping a wrist shot from Johansson with 1:31 left. One second later, Kuznetsov backhanded a shot on goal and Fleury reached his stick behind him to deny the shot just before it could cross the goal line.
Video: WSH@PIT, Gm3: Fleury extends for phenomenal save
Highlight of the game
Malkin passed from the goal line back to Schultz, allowing him to take a slap shot that tied the game. The goal was Schultz's first in 23 NHL career playoff games.
Video: WSH@PIT, Gm3: Schultz rips shot to tie game late
Unsung performance of the game
The Capitals killed the Penguins' five power plays, with each coming in the first two periods. The Penguins entered Monday converting 30 percent of their opportunities.
They said it
"I just said, 'It's another test for us.' You have to sort of park it and I think we've been really good at parking stuff. … We said, 'Let's just play.'" -- Capitals coach Barry Trotz on what was said before overtime
Video: WSH@PIT, Gm3: Trotz on team's power play in OT win
"[Washington is] a tough team to beat. It's a tough team to match up against. We found a way tonight to get back into it. It wasn't enough, but we'll go from there." -- Penguins forward Chris Kunitz
Need to know
Capitals defenseman Karl Alzner returned from an upper-body injury that had him miss six games. The Capitals dressed seven defensemen and mostly played with six after Niskanen was given the game misconduct. … Hornqvist, Dumoulin and Penguins forward Carl Hagelin played after Sullivan labeled them gametime decisions Monday morning. Hornqvist left Game 2 after blocking a shot off his leg with 4:18 remaining in the first period.
Game 4 of the Eastern Conference Second Round at PPG Paints Arena on Wednesday (7:30 p.m. ET; NBCSN, CBC, TVA Sports)
Video: Shattenkirk's OT goal leads Caps past Pens in Game 3