It was only the second Toronto win in its last 13 games.
John-Michael Liles scored a power-play goal 1:09 into the contest and Toronto's lead grew to 3-0 in the second period on goals from Joey Crabb and Jake Gardiner.
Martin St. Louis ended Reimer's shutout bid with 26 seconds left in the game. The Lightning lost for the fourth time in five games.
Dustin Tokarski got the start in goal for Tampa Bay and gave up three goals on 10 shots. Dwayne Roloson relieved Tokarski and stopped all 18 shots he faced.