ST. LOUIS: St. Louis goalie Brian Elliott earned his first career playoff shutout in a 1-0 overtime victory over the defending Stanley Cup champion Chicago Blackhawks on Wednesday night in the first game of the Western Conference quarterfinal series.

He made 35 saves and didn’t look at all like a player getting just his second playoff start in three years.

“You just try to get your emotions in check and try not to get too revved up, calm yourself down a little bit when needed,” Elliott said.

“At this time of the year it’s just about that next game. You’re not looking at the past or the future.”

In the opening games of the Eastern Conference quarterfinals series, Patric Hornqvist had his first playoff hat-trick as the Penguins beat New York 5-2, and Alex Killorn broke a third-period tie to lift Tampa Bay to a 3-2 win over the Detroit Red Wings.

At St. Louis, David Backes scored at 9:04 of overtime trying to go across the ice to Alexander Steen, and the pass deflected off a Chicago Blackhawks defenseman in front of the net.

It was Backes’ sixth career playoff goal and the first in overtime.

“I said out there, that’s an ugly goal and I specialize in those,” the Blues’ captain said. “Rightfully so. First shot of the game for me, too.”

Backes’ shot got past Corey Crawford after bouncing off Trevor Van Riemsdyk’s skate. Defensemen Jay Bouwmeester and Alex Pietrangelo assisted on the winner.

“I kind of felt it hit the inside of my pad and from there I was just hoping that it died,” Crawford said. “It was a tough bounce, but we’ve got to feel good about how we played.”

Elliott led the NHL with a .930 save percentage and was up to the task against a lineup led by scoring champion Patrick Kane and Jonathan Toews.

St. Louis cruised into the postseason with the third-best record in the NHL, winning eight of its last 10 games.

The Blues opened their previous series in 2014 against the Blackhawks with a pair of overtime victories, with Alexander Steen getting the winner in triple overtime in the opener. But Chicago won the last four, two in overtime.

The Blackhawks were 4-1 in overtime last season in the playoffs, including a double-overtime win at Nashville in Game 1 of their opening series.

“That’s the type of goal that gets scored in overtime,” Chicago defenseman Niklas Hjalmarsson said. “But they deserved it too, and we’ve got to find a way to score.’“

At Pittsburgh, Hornqvist scored three and added an assist, Sidney Crosby had a goal and two assists and backup goaltender Jeff Zatkoff did just fine in his first postseason start, finishing with 35 saves. Tom Kuhnhackl also scored for Pittsburgh, which took advantage when New York goalie Henrik Lundqvist left with a facial injury after the first period.

Lundqvist played just 20 minutes after taking a stick to the face from teammate Marc Staal. Antti Raanta was shaky in Lundqvist’s place, stopping 16 of 19 shots.

Derek Stepan scored twice for the Rangers, but New York never led as its quest to knock the Penguins out of the playoffs for a third straight year got off to an underwhelming start.

At Tampa Bay, Nikita Kucherov scored twice and Ben Bishop had 34 saves for the defending Eastern Conference champions, who got the winner from Killorn less than two minutes after a potential go-ahead goal was waived off when Detroit coach Jeff Blashill successfully challenged that Tampa Bay was offside before Victor Hedman scored.

Killorn took a feed from Tyler Johnson and slipped the puck past Jimmy Howard at 8:52 of the third.

Kucherov scored in the first and second periods and also assisted on the winner.