Michael Porter Jr. scored 25 points as reigning NBA champions the Denver Nuggets defeated the Miami Heat 100-88 on Wednesday to reclaim top spot in the Western Conference.

In a low-scoring clash between last year's NBA Finals rivals, Denver led for most of the first half before the Heat edged ahead with a third-quarter rally, only for the Nuggets to regain their advantage.

Denver pulled clear in the fourth quarter, with Reggie Jackson draining a 26-foot stepback three with just over three minutes remaining to put the Nuggets 10 points up at 94-84.

Nuggets star Nikola Jokic was restricted to 12 points after a disciplined Miami defensive effort, but that just allowed more space for Porter Jr., who drained five three-pointers in a 9-of-16 shooting display.

Denver's fourth straight victory saw them improve to 46-20, leaving them half a game clear of Oklahoma City at the top of the Western Conference.

It's the first time Denver have led the standings since November, suggesting Michael Malone's men are hitting form at the right time as they chase the top seeding for the playoffs.

In other games, Luka Doncic scored 21 points and Kyrie Irving 23 to lead the Dallas Mavericks to a 109-99 victory over the short-handed Golden State Warriors, who were missing the injured Stephen Curry and Draymond Green.

The only sour note for Dallas was the departure of Doncic midway through the fourth quarter, ending the Slovenian star's seven-game triple-double streak.

Doncic exited with tightness in his left hamstring and did not return.

In Florida, the Orlando Magic kept their push for a playoff berth on track with a 114-106 victory over the Brooklyn Nets.

Cleveland leapfrogged Milwaukee into second place in the Eastern Conference with a 116-95 win over the New Orleans Pelicans, who went into the game on the back of a four-game win streak.

In Indianapolis, DeMar DeRozan erupted for 46 points as the Chicago Bulls took down the Pacers 132-129 in overtime. (AFP)