Jason Terry added 18 points and Jerry Stackhouse had 16 for the Mavericks, who have won 22 of their past 24.
Ron Artest had 25 points, Kevin Martin added 21 and Corliss Williamson had 20 points for the Kings, who have lost 10 of their past 13.
The Mavericks won their 13th in a row at home, the second-longest home winning streak in franchise history behind a 16-game stretch last season.
Sacramento trailed by as many eight in the fourth quarter, but the Kings pulled within 101-100 on Mike Bibby's 22-footer with 46 seconds left. Nowitzki answered with a 16-foot fadeaway with 27 seconds to play to push Dallas' lead to 103-100.
Sacramento climbed back within one when Brad Miller's off-balance 3-pointer with 4.1 seconds to play made it 104-103, but Nowitzki's two free throws with 3.4 seconds remaining extended Dallas' lead to 106-103.