The Sabres' captain scored on a power play 56 seconds into overtime to give his surging club a 3-2 win against the Carolina Hurricanes at the First Niagara Center.
Now 7-1-2 in its last 10 games, Buffalo (31-28-8) is just two points back of eighth-place Winnipeg in the Eastern Conference. Thomas Vanek and Tyler Myers also scored for the Sabres, while Ryan Miller made 22 saves.
"It's huge. We're making steps," said Pominville, who also added an assist. "We're playing better hockey. We've dug ourselves in a big hole that isn't easy to get ourselves out of. But we believe."
Jaroslav Spacek and Chad LaRose scored for the Hurricanes, 2-1-4 in their past seven games. Coming off a 4-3 overtime win at Washington, Carolina failed to win consecutive road games for the first time since October.
"Our guys, you can tell by the way we're playing, we believe we can battle every night and keep picking up points," Hurricanes coach Kirk Muller said. "We're scratching and clawing for every point."
The Sabres converted with Bryan Allen off for hooking, in a penalty called with 55 seconds left in regulation. Parked atop the left circle, Pominville took a pass from Christian Ehrhoff and blasted it inside the far post. Goalie Cam Ward appeared to be screened by defenseman Jay Harrison.
Buffalo was 2-for-7 on the power play, the first time the Sabres have scored twice on the man-advantage in 31 games.
"Those penalties, we've got to be a little more smarter about that," Spacek said. "We didn't play a patient game in the end. A couple of penalties in the third period and it probably cost us the game."
Down 1-0 after Spacek opened the scoring 2:47 into the game, the Sabres carried much of the play in the second period. Buffalo scored twice in the first 1:02 and outshot the Hurricanes 14-4 through 12 minutes, and 17-8 overall in the period.
Myers tied it 22 seconds into the period when he blasted a shot from the right circle and the rebound caromed in off Carolina defenseman Justin Faulk.
Vanek scored 40 seconds later on a power play. Ward stopped Ehrhoff's point shot, but couldn't control the rebound. Parked in front, Vanek's initial backhander was stopped before he dug out the loose puck, turned toward the net and swept it in the open right side.
After LaRose tied it 5:11 into the period, the Sabres squandered numerous chances to regain the lead.
Alexander Sulzer was left wide open in the left circle, only to have his shot strike the far post at the 9-minute mark. Two minutes later, Vanek missed the net with a one-timer from the high slot. And then Drew Stafford missed the open side after being set up in front by Tyler Ennis.
Ward did his part, too. He was also exceptionally sharp in getting his stick and right pad on Brad Boyes' one-timer from the right circle early the second period.
And then there were a pair of saves Ward made in the final seconds of regulation. First he got his blocker out to stop Vanek's hot shot from the right circle. And then, just before time ran out, Ward hugged the right post to stop Boyes on two chances.
The Hurricanes squandered a chance of their own to pull ahead 6:29 into the third period. That's when Buffalo's Derek Roy was penalized for hooking, providing Carolina a two-man advantage spanning 1:21.
The 'Canes didn't manage a shot during the two-man power play, and the Sabres wound up having the best scoring opportunity while down one player. Ward got his left pad out to foil Matt Ellis, who was set up by Drew Stafford on a 2-on-1 break.
Carolina forward Jussi Jokinen made a great defensive play with 2 minutes left, poking the puck off the stick of Sabres center Derek Roy, who broke up the middle on a partial break.
"It's nice to have a chance at it," Miller said of a playoff spot. "We just have to be excited for this opportunity. There's a lot of hockey left to be played."
Material from wire services and team media was used in this report.
1 - 0 CAR
1 - 1 Tie
2 - 1 BUF
2 - 2 Tie
3 - 2 BUF