CHICAGO — After a wild and eventful night at the United Center, the Chicago Blackhawks have pulled off the improbable.

They’ve drawn even after losing the first three games to the Vancouver Canucks, the team with the best record in the NHL this season.

Now, do the defending Stanley Cup champions have one more left?

Ben Smith scored at 15:30 of overtime Sunday night, giving Chicago a 4-3 victory and sending the spirited and physical opening-round series back to Vancouver for Game 7 on Tuesday night.

“Anything can happen in Vancouver,” said Smith, a rookie who made his NHL debut in October. “I’m just trying to take a deep breath every once in a while. … They’ve got some great players. It’s nerve racking when they’ve got the puck. They really took it to us for a while.”

The Canucks played what coach Alain Vigneault characterized as their best game of the series. They made a goalie switch, turning to Cory Schneider in place of Roberto Luongo, who was pulled in the two previous games when he gave up 10 goals on 40 shots.

They still couldn’t win.

And Schneider couldn’t finish. When Chicago’s Michael Frolik tied it on a penalty shot in the third, Schneider was injured while trying to make the save and it was Luongo on in relief.

“I just lost my legs and I seized up and couldn’t do anything after that,” Schneider said.

Chicago is attempting to become the fourth team in NHL history to win a seven-game series after falling behind 3-0. Philadelphia did it last year against Boston in the Eastern Conference semifinals.

“We just kept pushing,” Vigneault said. “We need to find a way to change the momentum. Obviously, changing the goaltender and changing a few things up front were a way to try to get some of that momentum back. I thought we could have put it away, but we didn’t. We’re down to one game and we’re going to play real hard.”

Daniel Sedin, Alexandre Burrows and Kevin Bieska scored for the Canucks. Bryan Bickell and Dave Bolland added goals for the Blackhawks.

Also on Sunday:

Predators 4

Ducks 2

NASHVILLE, Tenn. — Nick Spaling scored his second goal of the game at 4:53 of the third period and Nashville closed out its first postseason series victory to advance to the Western Conference semifinals, beating Anaheim.

Steve Sullivan scored a goal, David Legwand had an empty-netter and Jordin Tootoo assisted on Spaling’s goals. The Predators won the series 4-2 in their sixth postseason in seven seasons.

Flyers 5

Sabres 4

BUFFALO, N.Y. — Ville Leino scored 4:43 into overtime to lift Philadelphia to victory and force Game 7 of their first-round playoff series against Buffalo.

Danny Briere scored twice while Brian Boucher stopped 24 shots in the latest Flyers goalie shuffle. Boucher took over to start the second period after Michael Leighton allowed three goals on the first seven shots he faced.