Smolinski scored from the slot 2 minutes into the third after taking Tony Salmelainen's centering pass from behind the net. Jeff Hamilton set up the play by forcing Montreal's Janne Niinimaa to turn over the puck. Montreal (3-1-2) lost for the first time in regulation this season.
Martin Havlat, who entered the game as the league's leading scorer, also scored for Chicago (4-2-0) but was held to one point in a game for the first time this season.
Chris Higgins, the Canadiens' leading scorer, recorded his fourth goal and David Aebischer made 21 saves for Montreal.
Nikolai Khabibulin had 28 stops for Chicago.
Havlat put the Blackhawks in front with his seventh goal just 49 seconds into the game. Carrying the puck down the right wing, he skirted past the Montreal defence and cut toward the net. Havlat then slid an off-speed backhand shot between Aebischer's legs.
Higgins tied it with 2:04 left in the first, just two seconds after a Montreal power play expired. After Khabibulin stopped Higgins' first shot from the left circle, he fired in the rebound from a sharp angle.
The Canadiens outshot the Blackhawks 9-4 in a scoreless second and forced Khabibulin to make several close-in saves.
Chicago survived the final 1:58 of the third playing short-handed. Aebischer was on the bench for a sixth attacker for the final 57 seconds.
Notes: Higgins has points in five of Montreal's first six games. ... The Canadiens, who defeated Calgary 5-4 in Montreal on Tuesday, didn't hold a game-day skate Wednesday morning. ... Montreal D Mathieu Dandenault missed the game with a thigh injury. Canadiens F Aaron Downey sat out with a concussion. Both are out indefinitely. ... Chicago forwards Denis Arkhipov and Reed Low were healthy scratches.