Jim Vandermeer also scored for the Blackhawks. Rostislav Olesz and Denis Shvidki scored for the Panthers (0-4).
Nikolai Khabibulin made 27 saves for Chicago (2-0) in his first preseason action.
Smolinski ended the game when he took a loose puck off the boards, skated to between the circles and beat Florida goalie Craig Anderson to his glove side with a slap shot. Anderson made 31 saves for the Panthers.
Smolinski was acquired along with left wing Martin Havlat from Ottawa in the three-team trade that sent Mark Bell to San Jose. Havlat made his Chicago debut Thursday, skating 28 shifts and putting two shots on goal.
The Blackhawks went up 2-0 with two power-play goals. With a two-man advantage in the first period, Smolinski took a pass from Jeff Hamilton at the red line and flicked in a shot that ricocheted off Anderson's blocker four minutes into the game.
The second power-play goal came in the second period when Hamilton took a pass from Rene Bourque and zipped a pass to Vandermeer, who sent a one-timer from between the circles.
Florida's goals game in the closing minutes of the second and third periods.