Evan Rodrigues also had a goal for the Sabres (20-33-11).
Cory Conacher scored for the Lightning (43-17-4).
Buffalo's Chad Johnson recorded 21 saves, while Tampa Bay's Andrei Vasilevskiy had 32 stops.
On a four-on-three power play that carried over into overtime after Adam Erne's illegal check to the head against Johan Larsson, Pominville one-timed his 10th goal through Vasilevskiy's pads for the win.
Vasilevskiy shut out the Sabres 2-0 on Nov. 28, but Buffalo, owners of the second-worst mark in the NHL, earned a 5-3 win over the Lightning on Feb. 13 and was the more aggressive club in the first period Wednesday.
The Sabres outshot Tampa Bay 11-6 over the first 20 minutes, but the Lightning killed off the lone power play to keep the game scoreless until Conacher scored at 18:03.
Yanni Gourde brought the puck into the offensive zone and dropped a pass back to trailing defenseman Dan Girardi, who fired a long shot on Johnson.
Conacher, standing unguarded in the low slot, collected his own rebound, put the puck on his forehand and flipped it over Johnson for his seventh goal and a 1-0 lead.
Scott Wilson and Rodrigues both hit the post for Buffalo, and Brayden Point did as well on a breakaway in a wild middle of the second period.
Rodrigues scored his sixth goal at 11:47 of the third when he beat Vasilevskiy on the glove side to tie it.
Tampa Bay was playing without NHL leading scorer Nikita Kucherov, who was injured against Toronto on Monday. His 82 points lead Pittsburgh's Evgeni Malkin by six. Kucherov has led the league in scoring continuously since Dec. 12.
Newly acquired forward J.T. Miller played in his first game for the Lightning, while defenseman Ryan McDonagh, who is injured but skated in practice, did not. McDonagh has an upper-body injury and has missed the past 10 games. Both were dealt from the New York Rangers to Tampa Bay on Monday before the league's trade deadline.
--Field Level Media
Buffalo | Tampa Bay | |
Jason Pominville 2 | Points | Cory Conacher 1 |
Jason Pominville 1 | Goals | Cory Conacher 1 |
Jason Pominville 1 | Assists | Dan Girardi 1 |
Jason Pominville 1 | Power Play Goals | N/A |
N/A | Short Handed Goals | N/A |
Chad Johnson .955 | Save Percentage | Andrei Vasilevskiy .941 |
Chad Johnson 21 | Saves | Andrei Vasilevskiy 32 |
Team | Shots | Goals | Power Play | Penalty Kill | Penalty Mins | Face Offs Won |
Buffalo | 34 | 2 | 1-4 | 1-1 | 2 | 25 |
Tampa Bay | 22 | 1 | 0-1 | 3-4 | 18 | 25 |