Connor Murphy, Oliver Moore, Landon Slaggert and Louis Crevier each had a goal and an assist for the Blackhawks (18-18-7). Matt Grzelcyk had two assists, and Spencer Knight made 27 saves.
Tyler Tucker, Otto Stenberg and Nathan Walker scored for the Blues (17-19-8), who had won two in a row. Jordan Binnington made 28 saves.
The Blackhawks were 3-for-4 on the powerplay. The Blues were 0-for-5.
St. Louis made it 1-0 on the first shot of the game after Tucker scored from in front off Brayden Schenn’s pass from below the goal line just 27 seconds into the first period.
Lardis tied it 1-1 with a power-play goal at 9:26 when he one-timed Moore’s cross-ice pass from the right face-off circle.
Moore put Chicago up 2-1 on the power play at 7:41 of the second period with a wrist shot from above the left circle that went in off Binnington’s glove.
Stenberg’s first NHL goal evened it 2-2 just 41 seconds later at 8:22. He forced a turnover in the offensive zone and lifted a wrist shot short side under the crossbar from low in the left circle.
Murphy gave the Blackhawks a 3-2 lead with his first of the season at 8:57 when his slap shot from the high slot squeaked through Binnington.
Slaggert made it 4-2 at 12:27 after Colton Dach’s point shot deflected off him from in front.
Jason Dickinson pushed it to 5-2 at 17:24. Crevier sent a slap shot from above the right circle that Dickinson tipped past Binnington from the slot.
Andre Burakovsky scored during a 5-on-3 power play at 5:11 of the third period to make it 6-2.
Crevier increased the lead to 7-2 at 12:56 when he backhanded the puck in after it deflected off the skate of Slaggert into the slot.
Walker batted the puck out of the air past Knight at 13:19 for the 7-3 final. Walker had not played since Dec. 1, missing the previous 16 games with an upper-body injury.
Prior to the game, the Blackhawks held a moment of silence and videoboard tributes to Hockey Hall of Fame members Glenn Hall and Bob Pulford, both of whom died this week. Hall was a goalie for Chicago from 1957-67. Pulford served the team as coach, general manager and as an executive.