Jason Pominville and Marcus Foligno each scored 3, in a battle between playoff hopefuls.
Drew Stafford had a goal and two assists for the Sabres, who remained two points back of Washington for the eighth and final playoff spot in the Eastern Conference. Corey Tropp and Brad Boyes also lit the lamp.
Ryan Miller made 24 saves for Buffalo, which snapped a two-game skid.
Ryan Malone and Bruno Gervais each had a goal and an assist for the Lightning, who were trying for their first regular-season series sweep over the Sabres in franchise history. Trevor Smith also scored.
Dustin Tokarski started the game for Tampa Bay and stopped 11-of-15 shots. Dwayne Roloson turned aside 20-of-23 shots in relief.
The Lightning, who fell to 1-4-0 on a seven-game homestand, have 71 points and sit nine points back of Washington. The Capitals beat the Red Wings on Monday.