The Mavericks took a seven-point lead into the fourth quarter, but failed to score a point over the final 2:06 while the Nuggets were rallying.
The win was tempered, however, by what appeared to be a serious knee injury suffered by the Nuggets' Danilo Gallinari, who yelled out in pain when he hit the floor with less than 5 minutes remaining in the second period.
Team officials said Gallinari will undergo an MRI Friday. He is averaging 16 points a game this season.
Denver won for the 18th time in 20 games and improved to 34-3 at home. The loss further dimmed Dallas' fast-fading playoff hopes.
Andre Miller led the Nuggets with 22 points and Kenneth Faried contributed 12 points and 19 rebounds.
Brandan Wright scored 16 points off the bench for the Mavericks.