The Brooklyn Nets pulled off a 4-1 series win over the Boston Celtics, while reigning champions the Los Angeles Lakers are on the edge of elimination.
The Lakers, without Anthony Davis, suffered a 115-85 defeat to the Phoenix Suns and trail 3-2 in the best-of-seven series.
Elsewhere, the Denver Nuggets clinched a 147-140 win in double-overtime against the Portland Trail Blazers.
The Blazers' Damian Lillard scored 55 points including a play-off record 12 three-pointers in defeat.