Gonchar withstood two misplays that led to Washington goals by scoring in overtime after Darryl Sydor had tied it late in the third period as the Pittsburgh Penguins rallied to beat the Capitals 4-3 on Thursday night.
Crosby, winning his head-to-head matchup against Alexander Ovechkin as usual despite Ovechkin's 26th goal, controlled the puck behind the net, carried it into the slot and faked a shot before throwing it into the right circle for Gonchar's seventh goal.
Before that, Gonchar -- playing without usual defenseman partner Mark Eaton -- was on the ice with new partner Rob Scuderi for all three Capitals goals. Eaton is out indefinitely with a torn right anterior cruciate knee ligament.
"I had a couple of mistakes, and I didn't feel great about this one, but I scored a goal and I feel a lot better now," Gonchar said. "Sid made a great pass. When he started skating toward the net, both defensemen are paying attention to him and not even looking at me. I had a wide-open net."
Washington's Olaf Kolzig made 16 saves after Brent Johnson sprained his left knee late in the first period as Washington turned a 2-1 deficit into a 3-2 lead, only to give up two goals in little more than three minutes. Sydor's power-play goal, his first in 31 games since signing with Pittsburgh, came with 2:16 left in regulation. Gonchar won it 1:33 into overtime.
Crosby had two assists, giving him 17 points in 10 career games against Ovechkin -- nine of them Penguins victories. Ovechkin, who has four goals and 10 points against Pittsburgh, played only about a minute in the third period before needing several stitches to repair a cut on his leg and didn't return. The injury is not serious.
Still, Ovechkin's absence may have prevented Washington from putting the game away.
"I thought we had total control over the last half of that game, until we took a penalty," coach Bruce Boudreau said. "It is a game we have to win."
Instead, the Penguins -- losers of four of six before the holiday break -- forced the overtime with Sydor's goal on a slap shot from the high slot with four seconds remaining on Shaone Morrisonn's roughing penalty. Sydor's goal was his first since March 2 for Tampa Bay against Columbus.
"They were trying to shut things down, but we got a big goal there from Syd [Sydor] to keep us in it," Crosby said. "Every game isn't going to have three solid periods and a perfect ending. This is what you have to do sometimes, find ways to win when you're not playing your best."
The Capitals, losing their fifth in seven games, had seized a 3-2 lead on Ovechkin's goal late in the second after Pittsburgh failed repeatedly on what usually is a routine play, clearing the puck behind its net.
Backstrom also assisted on Brian Pothier's tying goal about 5½ minutes into the second, faking a shot before dropping a pass to Pothier for a one-timer from the top of the right circle.
"I think the whole third period ... we just weren't ourselves," Pothier said. "We didn't have enough energy, we were turning the puck over. ... We ended up taking a penalty because they're flying and we're not."
Jeff Taffe and Colby Armstrong also scored for Pittsburgh. Armstrong made it 2-1 late in the first with a backhander from along the goal line that was intended as a pass for Evgeni Malkin but deflected off Milan Jurcina's stick and past Johnson.
Johnson sprained his left knee on the play and had to be helped off the ice as Kolzig took over. Johnson will be out at least a week.
Washington was coming off a 3-2 win over Tampa Bay on Wednesday. ... Crosby was held without a goal for the 11th time in 13 games. ... All 19 Penguins home games have been sellouts, and their 32-game sellout streak since last season is a club record. ... Penguins forward Ryan Malone (leg infection) missed a fifth consecutive game.