The Bucks escaped with the win when the Spurs' Richard Jefferson missed a potential score-tying 3-pointer as time was expiring.
Jackson also had eight assists, including one on Brandon Jennings' dunk with 50 seconds remaining that gave Milwaukee its final margin of victory.
Jennings totaled 15 points and 11 assists. Andrew Bogut returned after a four-game absence to post 14 points and 11 rebounds as the Bucks ended a five-game losing streak.
Notable deaths of 2014 [PHOTOS]
Michael Sam cut from the Dallas Cowboys