The Washington Capitals claimed the Southeast Division crown for a fourth straight year and took control of first place in the Eastern Conference as they beat the Toronto Maple Leafs 3-2 in a shootout.
In fact, they had already secured the division crown before their game was over, as the Tampa Bay Lightning's challenge ended in a 4-2 loss to the Buffalo Sabres, but Washington needed the win to go top in the conference.
The result, secured by Mike Knuble's goal in the fourth round of the shootout, also ended the play-off hopes of the Maple Leafs.
And lost somewhere in the significance of the results at this key stage of the season was the fact that Washington's opening goal made Alex Ovechkin, who is 25 years and 200 days old, the sixth-youngest player in NHL history to reach 300 goals when he scored 11:28 into the first period.
John Erskine also scored for Washington, while Nikolai Kulemin and Joffrey Lupul replied for the Maple Leafs.
Buffalo did Washington a favour with a 4-2 win, sealed by a late open net goal by Thomas Vanek as Tampa Bay desperately sought a tying goal.
The result keeps Buffalo's play-off hopes alive as they move seventh in the Eastern Conference.
The Pittsburgh Penguins are close to sealing home ice advantage for the opening rounds of the play-offs after a 4-2 win over New Jersey, which came thanks to two goals from Pascal Dupuis and strikes from Jordan Staal and Chris Kunitz.
The Montreal Canadiens booked their play-off spot with a 2-1 win over the Chicago Blackhawks, secured when PK Subban scored an overtime winner on a power play.
The Nashville Predators are closing in after Jordin Tootoo and Sergei Kostitsyn scored two apiece in a 6-3 win over the Atlanta Thrashers, moving them up to fourth in the Western Conference. One point from their final two games, or a Dallas defeat, will put Nashville in the post-season.
However, the Stars will not go quietly, and they beat the Columbus Blue Jackets 3-0 to stay in the hunt.
Steve Ott's first period goal was all that separated the teams heading into the final minute, but empty-netters from Loui Eriksson and Brenden Morrow made sure.
Western Conference leading Vancouver already have a play-off berth secured, which is just as well considering a 2-0 loss to the woeful Edmonton Oilers in a top-versus-bottom clash.
Elsewhere, Jason Spezza had a goal and three assists as the Ottawa Senators beat the Philadelphia Flyers 5-2, while the St Louis Cardinals beat the Colorado Avalanche 3-1.
