Nowitzki finished with 22 points and his jumper heading into the closing minute produced the last points Dallas could manage. Golden State failed to capitalize, however, missing its final four shots.
Jose Calderon and Jae Crowder both scored 12 points for the Mavericks, who bounced back from their first home loss of the season to improve their record in Dallas to 8-1.
It was Golden State's fourth loss in five games. Dallas had dropped its previous two outings, both of them to Denver.