Blues forward Vladimir Tarasenko scored twice and has an NHL-leading four goals in the playoffs.
Blackhawks forward Jonathan Toews had two assists in the win. He has a team-high five points in the series.
The Blues scored twice in the final two minutes of the second period. Five of their 11 goals in the series have come in the final two minutes of periods.
The game included nine penalties, but none were called after the second period.
Toews won 12-of-23 faceoffs. He's won 68-of-106 for a 64.2 percentage in the series.
The Blues were 1-for-5 on the power play and are 2-for-21 for in the series.
The Blackhawks were 1-for-2 on the power play and are 2-for-16 in the series.
Blackhawks defenseman Nick Leddy had a game-high 83.9 Corsi percentage (the Blackhawks had 26 shots for and five against when he was on the ice in 5-on-5 situations,) according to extraskater.com.
The Blackhawks had 15 players with a Corsi percentage greater than 50 percent. The Blues had two.
Blues defenseman Alex Pietrangelo had a game-high 28:55 of ice time. He leads the league with 127:16 of ice time in the playoffs.
The Blues blocked 25 shots and the Blackhawks blocked 17.
Blackhawks forward Patrick Sharp started nine of his 14 shifts in 5-on-5 situations in the offensive zone. He had a game-high 10 shot attempts, including seven on goal.
Blackhawks defenseman Niklas Hjalmarsson blocked four shots and is tied for first in the league with 18 in the playoffs.
Hjalmarsson led the Blackhawks with 28:43 of ice time. It was the first time in the series that Duncan Keith didn't lead the Blackhawks in ice time.