Lukas Krajicek, Jeff Halpern and Cory Murphy also scored in Tampa Bay's fifth victory in seven games. Lecavalier and St. Louis, who combined for 14 goals and 22 assists over the previous 12 games, did not have a point.
"It's nice to get other guys scoring," Tampa Bay interim coach Rick Tocchet said. "Eighty-two game schedule, you've got to have that if you're going to win."
Lecavalier and St. Louis did have six combined shots.
"Vinny and Marty carry this team all year," Halpern said. "Even if they don't get points or score, I thought those guys tilted the ice for us at times when the other team was pushing. I think the way our team is playing these last few weeks, we're getting goals as a team."
"They had their chances and they put them in the back of the net," Roy said.
Sabres goalie Ryan Miller, who entered 7-1 with a 1.94 goals-against-average in January, gave up five goals on the first 21 shots he faced.
Buffalo defenseman Henrik Tallinder left the game with what could a major shoulder injury.
"Henrik's not good," Buffalo coach Lindy Ruff said. "We'll probably get him back to Buffalo and that will be looked at, but he's going to be out for a good period of time probably."
Eminger scored a power-play goal 4:45 into the game, and Downie put Tampa Bay up 2-0 at 5:19.
Both teams scored three goals and combined for 34 shots in the wild second period.
Roy got the Sabres to 2-1 on a rebound goal 19 seconds into the second.
Krajicek snapped a personal 64-game goal drought - dating to Nov. 29, 2007 - on a flukey goal at 1:23 of the second that made it 3-1. The rebound of his shot went off Buffalo's Thomas Vanek and into the net.
After Kotalik scored with the man advantage at 4:04, Halpern gave Tampa Bay a 4-2 advantage during a 2-on-1 with 6:08 left in the second.
"I don't know if we deserved to win tonight," Kotalik said.
The teams traded late second-period power-play goals. Roy got his second goal of the game at 16:55, and Murphy scored his first goal in 31 games with 5.8 seconds remaining.
Notes: Tampa Bay RW Mark Recchi played in his 1,457th game, tying him with Glen Wesley for 16th place on the career NHL list. Recchi's two assists Wednesday gave him 1,412 points, two short of tying Doug Gilmour for 16th place. ... Tampa Bay recalled D Ty Wishart on an emergency basis from Norfolk of the AHL. He picked his first career point with an assist on Halpern's goal. ... The Lightning reassigned D Kevin Quick to Norfolk.
|PPG - Steve Eminger (4) ASST: Jeff Halpern (5)|
1 - 0 TBL
|Steve Downie (2) ASST: Cory Murphy (3), Matt Pettinger (4)|
2 - 0 TBL
|Derek Roy (17) ASST: Jason Pominville (24), Toni Lydman (12)|
2 - 1 TBL
|Lukas Krajicek (1) ASST: Andrej Meszaros (13), Vinny Prospal (19)|
3 - 1 TBL
|PPG - Ales Kotalik (10) ASST: Craig Rivet (7), Paul Gaustad (7)|
3 - 2 TBL
|Jeff Halpern (3) ASST: Mark Recchi (20), Ty Wishart (1)|
4 - 2 TBL
|PPG - Derek Roy (18) ASST: Thomas Vanek (15), Jason Pominville (25)|
4 - 3 TBL
|PPG - Cory Murphy (1) ASST: Mark Recchi (21)|
5 - 3 TBL
|Daniel Paille Hooking against Steven Stamkos|
|Adam Mair Elbowing against Cory Murphy|
|Martin St. Louis Tripping against Derek Roy|
|Jeff Halpern Hi-sticking against Nathan Paetsch|
|David Koci Roughing against Daniel Paille|
|Paul Gaustad Roughing against David Koci|
|David Koci Roughing against Paul Gaustad|
|David Koci Interference against Derek Roy|
|Chris Butler Tripping against Ryan Malone|
|Henrik Tallinder Tripping against Vincent Lecavalier|
|Lukas Krajicek Interference against Drew Stafford|