CHICAGO -- St. Louis Blues left winger Jaden Schwartz knew exactly what to do on the power play.

Teammate Vladimir Tarasenko set up at the point with the puck. David Backes stationed his 6-foot-3, 221-pound frame at the side of the net. Schwartz skated to the low slot and stayed ready.

"It's quick," Schwartz said.

The sequence worked to perfection as Tarasenko zipped a pass to Backes, who quickly fed a pass to Schwartz for a go-ahead goal late in the third period. The Blues held on for a 3-2 win over the Chicago Blackhawks on Sunday afternoon.

St. Louis seized a 2-1 lead in the best-of-seven Western Conference quarterfinal. Game 4 is scheduled for Tuesday in Chicago.

Colton Parayko and Patrik Berglund also scored for the Blues, who erased a one-goal deficit with back-to-back goals in the third period.

Before Sunday's loss, Chicago was 70-0-4 when leading after two periods since the start of 2014-15.

"It's the first round, but it feels very much like a final," St. Louis coach Ken Hitchcock said. "Both teams are just laying it all out there. I like the fact that we've got home ice back again."

Brent Seabrook and Artem Anisimov scored for the Blackhawks. A four-minute high-sticking penalty on Patrick Kane preceded the Blues' game-winning goal on the man advantage.

St. Louis goaltender Brian Elliott stopped 44 of 46 shots to earn the victory.

Chicago goaltender Corey Crawford turned aside 33 of 36 shots.

"Give their goaltender credit, I think he played a great game again," Blackhawks center Jonathan Toews said. "At the same time, so did ours. Even though we outshot them, I think we still gave up a few too many scoring chances. Those games could go either way."

Schwartz scored on the power play to give St. Louis a 3-2 lead with 6:38 to go in the third period. The Blues finished 2-for-3 on the power play after going 0-for-5 in the first two games of the series.

Schwartz said confidence played a large role in the Blues' comeback in a hostile environment.

"We just had that positive feel going out in the third period," Schwartz said. "There was never a doubt that we couldn't win this game. It's nice to see us get rewarded there and to stay with it."

Chicago opened the scoring 2:18 into the first period on a power-play goal by Seabrook. Toews won a faceoff in the offensive zone and fed a pass to Seabrook moments later. Seabrook fired a slap shot through traffic as left winger Andrew Ladd set a screen in front of the net.

St. Louis evened the score at 1 on a power-play goal by Parayko with 7:49 to go in the first period. Defenseman Alex Pietrangelo zipped a pass to Parayko, who blasted a one-timer from the top of the left circle for his first career playoff goal.

Anismov put Chicago back on top 2-1 during four-on-four play with 18:56 left in the second period. Left winger Artemi Panarin pried the puck loose along the boards and slipped a backhand pass to Anisimov in front of the net. Anisimov botched the one-timer but made enough contact to send a fluttering puck past Elliott for his first goal of the series.

Chicago fired 24 shots on goal during the second period but failed to increase its lead.

"We were in a great spot," Chicago coach Joel Quenneville said. "Probably had more chances in the second than any period we had all year. It was still a one-goal game, though."

Berglund scored as St. Louis pulled even at 2 with 14:45 remaining in the third period. Berglund carried the puck across the blue line and released a low wrist shot. The puck deflected off the leg of Blackhawks defenseman Michal Rozsival and skipped into the net before Crawford could react.

"It was a lucky bounce," Berglund said, "but it doesn't matter how they go in."

NOTES: Blues C Steve Ott returned to the lineup for his first time since Dec. 5. Ott, 33, missed more than four months after undergoing surgery on both of his hamstrings in December and battling colitis earlier this month. ... Blackhawks RW Dale Weise appeared in his first playoff game with Chicago after sitting out the first two games of the series as a healthy scratch. Weise, 27, appeared in 34 playoff games with the Vancouver Canucks and Montreal Canadiens in the previous four seasons. ... Blues RW Ryan Reaves was a healthy scratch after playing in the first two games of the series. ... Blackhawks LW Andrew Desjardins was a healthy scratch for the first time during the series. ... Blues RW Dmitrij Jaskin and LW Magnus Paajarvi were healthy scratches for the third consecutive game.