St. Louis made several stick-handling moves on Ryan Miller after getting the puck while alone in the low slot, and lifted a shot over the goalie to make it 2-0 with 11:30 left. Victor Hedman added an empty-net goal, which St. Louis assisted on.
Garon made 21 saves to post his first shutout in 34 games, dating to Nov. 20, 2010, against San Jose. He is 2-8 against Buffalo.
Pavel Kubina also scored for the Lightning, who have won two in row following a five-game skid.
Sabres left wing Thomas Vanek had his season-opening, six-game point streak snapped. He had six goals and 10 points during the stretch. Buffalo dropped to 4-1 on the road this season.
Kubina put the Lightning ahead 1-0 when he beat Miller from just inside the blue line at 4:51 of the second. Miller, coming off a 22-save shutout in Buffalo's 3-0 win Thursday at Florida, fell to 17-5 against the Lightning.
Roloson keyed Tampa Bay's run to the Eastern Conference finals last season, in which the Lightning lost in seven games to Boston.
Notes: Jim Craig, the goalie for the gold-medal winning 1980 United States Olympic hockey team, was at the game. ... Sabres C Tyler Ennis left after playing just one shift due to an undisclosed lower body injury. ... Tampa Bay D Marc-Andre Bergeron had his five-game point streak (two goals and six assists) end. ... Vanek entered with 22 goals in 24 games against Tampa Bay.