MIAMI (AFP) — Michael Porter Jr. scored 25 points as reigning National Basketball Association champions 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 step-back three-pointer 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.

Porter Jr. said his impressive performance owed everything to his teammates engineering time and space for him to shoot freely.

"Did you see the shots I was getting? They were wide open threes, so it's really my teammates, all credit to them," Porter Jr. told ESPN.

"We've got a good, well-balanced team so when you take something away, there's another option. That's what it was tonight."

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.