The Miami Heat secured a play-off spot with a 129-121 win at the Boston Celtics that all but condemned the Celtics to the new play-in tournament.
Meanwhile, the Los Angeles Lakers kept their play-off hopes alive with a 101-99 victory against the New York Knicks.
With LeBron James again absent through injury, Talen Horton-Tucker stepped up to hit the match-winning three-pointer.
The Lakers are hopeful James, who has missed their past five games with an ankle injury, can play against the Houston Rockets at home on Wednesday.
The result leaves the seventh-placed Lakers within one place of the Dallas Mavericks, who lost 133-104 to the Memphis Grizzlies.
The top six teams in each conference qualify directly for the play-offs, while teams finishing seventh to 10th compete for two further play-off places via the new play-in tournament.
The Chicago Bulls are currently on track to miss the post-season entirely, sitting in 11th place after a 115-107 loss to the Brooklyn Nets.
Elsewhere, the Denver Nuggets beat the Charlotte Hornets 117-112, the Minnesota Timberwolves recorded a 119-100 victory against the Detroit Pistons and the LA Clippers claimed a 115-96 win against the Toronto Raptors.
The Indiana Pacers, Milwaukee Bucks, Golden State Warriors and Sacramento Kings were also victorious as the final week of the regular season continues.