(Paul Beaty ~ Associated Press)
Kane scored on a rebound off a shot by Viktor Stalberg with 6 minutes, 18 seconds left to put the Blackhawks up 6-4 after they nearly let a 5-1 lead slip away in their first home game since going 4-2 on a road swing out West.
Toews then added his second power-play goal of the night about 2 minutes later to give Chicago a three-goal cushion on its way to a third straight win.
David Backes scored for St. Louis with 2:39 left, but the Blues couldn't come all the way back and lost their third consecutive game.
Tomas Kopecky had a goal and three assists while Patrick Sharp and Troy Brouwer also scored for Chicago. Rookie goalie Corey Crawford ran his winning streak to five games, holding off the Blues' rally. He made 21 saves.
Patrik Berglund, Eric Brewer, Alex Pietrangelo and Brad Boyes scored goals for the Blues, while Backes and Vladimir Sobotka had three assists apiece.
Playing without injured forward Marian Hossa, the Blackhawks appeared to build a comfortable lead with three second-period goals against Blues backup goalie Ty Conklin.
But St. Louis, which did some switching with its top two lines to start the game, rallied with three goals in an 8:32 span of the second and third periods to make it a one-score game.
Hossa is expected to miss two to three weeks with a lower-body injury after colliding with teammate Nick Boynton during practice Monday.
Brewer's shot from the slot late in the second period eluded a screened Crawford and made it 5-2.
Pietrangelo's long slap shot from beyond the right circle made it 5-3 early in the third and Boyes' rebound about 3 minutes later cut it to one, prompting the Blackhawks to take a timeout.
NOTES: Sharp, the Blackhawks' leading scorer, has goals in five straight games. ... The Blues had managed just three goals in their previous two games, both losses to Dallas.