Tyler Bozak scored with 2:05 left in the third period off Maroon's assist to give the Blues a 2-1 victory over the Winnipeg Jets on Wednesday night in Game 1 of their Western Conference opening-round playoff series.
Maroon sent a backhand pass from behind the net out to Bozak in the slot, and Bozak's quick shot went by Winnipeg's Connor Hellebuyck for the go-ahead goal.
David Perron also scored for St. Louis early in the third, and Jordan Binnington made 24 saves.
Patrik Laine scored late in the first period and Hellebuyck stopped 24 shots for the Jets, who host Game 2 on Friday.
St. Louis outshot the Jets 8-7 in the opening frame, with Laine having two shots.
Jets defenseman Dustin Byfuglien helped divert a St. Louis goal early in the second period. Vladimir Tarasenko fired a shot at Hellebuyck and the puck trickled out from under him toward the goal line, but Byfuglien swooped in and slapped it out of the crease.
Winnipeg's penalty kill worked twice more in the second period. Binnington then came up big on a backhand breakaway shot by Par Lindholm and a quick shot from Andrew Copp.
The Jets got their first power play of the game with 3:09 left in the middle frame. Byfuglien had his team's two shots with the man advantage - one was stopped and the other hit the post.
Laine rang a shot off the post just over one minute into the third, followed by Perron's point shot through traffic that went by Hellebuyck to tie it up at 4:05. The Winnipeg netminder blocked a Bozak shot late in the period and then couldn't stop the winner.
Hellebuyck was pulled right away for the extra attacker, but Binnington slid across his crease to make an impressive pad save on Scheifele's one-timer with under 12.4 seconds left.