Shawn Marion scored 11 of his 19 points in the fourth quarter for Dallas, which probably took extra satisfaction finally handing the Spurs a loss. Last time the Mavs were in San Antonio, their season ended in a stunning playoff ouster to the Spurs.
Manu Ginobili had 31 points for the Spurs, 16 in the first quarter.
But the Mavericks, who lost all three playoff games in San Antonio in their first-round loss last season, pulled away with a 14-2 run within the final five minutes.
Tyson Chandler scored 13 of his 19 points from the foul line for Dallas, which has won four straight.