Pittsburgh Penguins captain Sidney Crosby was quick to back goaltender Louis Domingue, following their 5-2 loss to the New York Rangers on Thursday.

The Rangers tied their playoff series up at 1-1 after Pittsburgh's 4-3 win in triple-overtime at Madison Square Garden on Tuesday.

One of the key figures in that overtime win, Domingue was given a start by Penguins coach Mike Sullivan, but gave up key goals to Ryan Strome and Chris Keider via deflections.

Crosby backed his teammate following the loss, bringing saves he did make with Game 2 in the balance in perspective.

"The fourth was a bad bounce, a couple of tips there," Crosby said. "I thought he [Domingue] was solid. I thought he made some big saves, especially when there was a one or two-goal difference, that kept us in it."

The two-time Hart Memorial Trophy winner believes the Penguins simply need to start better and put three periods of hockey together to progress past the Rangers.

"It's the playoffs," Crosby said. "There are going to be swings of momentum but I thought that in both games, as they've gone on, we've probably gotten better. We just have to find a way to come out of the gates a bit better.

"You don't want to get down two, we've done that a couple of times now. It's not something we want to make a habit of.

"We get that late one and we had some really good chances early in the third and didn't convert, and they got a bounce. That's what it came down to."

In other NHL playoff results on Thursday, a Cale Makar goal gave the Colorado Avalanche a 2-1 overtime win over the Nashville Predators, moving to 2-0 in their series.

Meanwhile, the Dallas Stars and Florida Panthers tied up respective series with the Calgary Flames and Washington Capitals.

Evgeni Malkin says the Pittsburgh Penguins "deserved to win" after he scored the decisive goal 5:58 into the third overtime of their 4-3 victory over the New York Rangers in the NHL playoffs on Tuesday.

The Penguins take a 1-0 lead in their Stanley Cup playoff opening-round series, where goalies Igor Shesterkin and Louis Domingue were outstanding for both sides.

Penguins back-up goalie Domingue came in for Casey DeSmith who exited due to cramping. Domingue starred with 14 saves in the second overtime and three more in the third.

"We know we can win every game if we play right," Malkin told reporters. "We play smart. We play hard. I think we deserved to win tonight."

The Rangers had led 2-0 after Andrew Copp doubled their lead in the second lead after Adam Fox's power-play goal in the first period.

The Penguins leveled it up after goals from Jake Guentzel in the second period, before Chris Kreider restored the Rangers' lead. Malkin found Bryan Rust to square the game up again, before it headed for overtime. Malkin came up with the decisive deflection.

The epic was the longest-ever NHL game played at Madison Square Garden.

On Domingue, Malkin added: "For me, I know Louis is unbelievable. He is big and he is fast. I wasn’t worried. It is hard to score on him in practice."

Washington Capitals forward Tom Wilson was injured as his side won 4-2 over the Florida Panthers in Game 1 of their series. Wilson had scored before going off with a lower-body injury.

Colorado Avalanche piled on five first-period goals as they routed the Nashville Predators 7-2 in Game 1 of their first-round playoff series.

Elias Lindholm's first-period goal proved the difference as the Calgary Flames got past the Dallas Stars 1-0.

The Calgary Flames' next three NHL games have been postponed amid a coronavirus outbreak in the team.

A total of six players and one staff member have entered NHL COVID-19 protocol, the league confirmed on Monday.

Forwards Elias Lindholm, Andrew Mangiapane, Brad Richardson and Adam Ruzicka, defensemen Christopher Tanev and Nikita Zadorov all entered protocol, along with a staff member.

The NHL suggested there may be further cases confirmed in the days ahead, with the team's training facilities closed until further notice.

The Flames (15-7-6) had been set to face the Chicago Blackhawks on Monday, but that game and the subsequent fixtures with the Nashville Predators and the Toronto Maple Leafs will be rescheduled. 

Saturday's game at home to the Columbus Blue Jackets is still set to take place.