Trey Burke scored a team-high 25 points and the shorthanded Mavericks held off the Thunder 106-103 Sunday afternoon in Oklahoma City.
The Thunder (44-33) fell a half game behind the Spurs in the Western Conference playoff race and are in sole possession of eighth place with five games left in the regular season.
Jerami Grant scored 10 of his 14 points in the fourth quarter, including a basket off an in-bounds pass with 32.8 seconds left that gave OKC a short-lived lead at 103-102.
Dwight Powell answered seconds later with a dunk that gave Dallas the lead for good.