On the road, against a division-leading club, the Sabres rallied from three one-goal deficits before Jason Pominville took Tim Connolly's feed in overtime, skated in alone and put the puck past Washington Capitals goalie Simeon Varlamov for a 5-4 win at Verizon Center.
"If you battle that hard, you're going to get rewarded," Sabres coach Lindy Ruff said.
Buffalo now has 85 points with five regular-season games remaining. The Sabres sit 10th in the Eastern Conference, two points behind Florida and four in back of the New York Rangers, who hold the eighth and final playoff berth and have four games left.
The point from the overtime loss was enough to clinch the Southeast Division for Washington, which has 102 points. The Capitals hold a two-point edge on New Jersey for the No. 2 seed with each team having four games remaining.
"You know what? It's an accomplishment, but it's an accomplishment we thought was going to happen," Caps coach Bruce Boudreau said of his team's second consecutive division title. "I mean, let's face it, Carolina would have to win 12 in a row and we'd have to lose all of our games. It would be a monumental collapse."
Once regulation ended and Washington was assured at least one point, the center-ice scoreboard displayed a message commemorating the second-straight division crown and U2's "Beautiful Day" played through the arena. But the fans' joy was short-lived.
With the teams skating 4-on-4, Pominville struck 1:51 into the extra period for his 17th goal of the season. Connolly, who finished with three assists, skated up the right side of the ice before finding Pominville streaking into the middle and setting up a breakaway.
"Their player fanned on a pass and Timmy ends up cutting it off. He just made a great play and I just had to pick a hole," Pominville said. "I looked glove and he had his glove there so I decided to shoot five-hole and it ends up going in, so I'll take it."
Drew Stafford, Clarke MacArthur, Derek Roy and Maxim Afinogenov also scored for the Sabres, who led 2-1 after the first period but fell behind early in the second after giving up a pair of power-play goals nine seconds apart. Ryan Miller made 33 saves.
"It's any way we can get points now," Miller said. "The boys battled through some tough stuff in the second period, it was just a parade to the penalty box for us. The 5-on-3s, this team’s good enough 5-on-4, but if you give them 5-on-3s … we spent a lot of energy there and to have enough energy to come back and really have a good third period was a great testament to how hard we want to work."
Alexander Ovechkin, Alexander Semin and Sergei Fedorov all had goals with the man advantage for the Capitals, and Fedorov added his second of the night at even strength to give Washington a 4-3 lead heading into the third. Varlamov stopped 25 shots and lost for the first time following wins in each of his first three NHL starts.
Afinogenov, who has scored as many as 23 goals in a season but entered Friday with just five in 44 games, forced overtime when he scored with 9:39 left in the third. It was atonement for a play earlier in the period when the Sabres thought they had the tying goal only to see it disallowed because Afinogenov made contact with Varlamov.
Penalty trouble put the Sabres behind the eight-ball in the second, as Semin and Fedorov scored in rapid-strike fashion to lift the Capitals from a 2-1 deficit to a 3-2 lead.
Derek Roy took a tripping call at 1:14 and Jaroslav Spacek was simultaneously sent off for holding. Before the Sabres could even kill off the 5-on-3, Toni Lydman was called for hooking at 2:39.
Semin finally tied the game at 3:41 when he poked home a Brooks Laich rebound while camped out near Miller's crease. Off the ensuing faceoff, with Washington still on a one-man advantage, the puck was worked into the Buffalo zone and Tomas Fleischmann made a diving play to keep it in, knocking it right to Fedorov who put a rising slap shot over Miller's shoulder.
"He was playing smart hockey today," Fleischmann said. "Those two goals were just [him being in a] smart position and [they were] nice shots, too. His experience is what we need."
Ovechkin opened the scoring 5:35 into the first with his League-leading 55th goal of the season. Stafford answered for the Sabres with his 20th at 9:14. MacArthur, whose hooking penalty led to Ovechkin's goal, was credited with his 16th when his attempted pass was deflected in by Viktor Kozlov of the Capitals 48 seconds after Stafford scored.
"Unfortunately, early on we were kind of caught in the box for a few of their goals, but again, we found a way and that's what counts," Pominville said. "We're still alive."
Material from wire services and team broadcast and online media was used in this report.