The Eastern Conference-leading Cleveland Cavaliers confirmed their superiority with a 104-93 victory over the Boston Celtics.
LeBron James scored 30 points and Antawn Jamison, back from injury, had 15 points and 12 rebounds as the Cavaliers scored another impressive win over an Eastern rival.
The battle for home-court advantage in the Western Conference remains as tight as ever, with the Oklahoma City Thunder, Phoenix Suns, and Portland Trail Blazers - who are fifth, sixth and eighth in the standings respectively - all winning.
Kevin Durant got 35 points and Russell Westbrook added 30 and 11 assists as the Thunder beat the fourth-placed Jazz 119-111, cutting Utah's advantage to one game.
The Suns are one game back on Oklahoma City after beating the New Orleans Hornets 120-106.
Amare Stoudemire had 36 points and 12 rebounds, while Steve Nash collected 13 points and 12 assists in his 1,000th NBA game.
Nicolas Batum got 22 points to help the Trail Blazers beat the Toronto Raptors 109-98.
The seventh-placed San Antonio Spurs were not in action.
The Charlotte Bobcats keep on rolling as Stephen Jackson had 28 points and Raymonds Felton 16 in a 96-89 victory over the Orlando Magic.
The win keeps Charlotte firmly on track for their first playoff appearance.
Dwyane Wade exploded for 38 points as the Miami Heat beat the Philadelphia 76ers to keep their playoff push on track.
It was a third straight win for Miami, who have a four game cushion over ninth place in the Eastern Conference.
Jerry Stackhouse scored 20 points and Andrew Bogut added 17 and 12 rebounds as the Milwaukee Bucks edged out the struggling Indiana Pacers 98-94.
Rookie Tyreke Evans had 29 points, 11 assists and nine rebounds as the Sacramento Kings beat the Minnesota Timberwolves 114-100.