Tony Parker (knee), Tim Duncan (knee) and Manu Ginobili (hamstring) were all scratched from the game but the Spurs leaned on a career-best 26 points from Kawhi Leonard and 18 from Danny Green to tame the Bulls.
San Antonio clung to a slim 76-75 edge in the fourth before running off a 19-5 spurt to close the door on Chicago.
The Spurs (41-12) had lately been relying on the brilliant play of All Star Parker who covered for his ailing team-mates and even as he too joined the injured group with a swollen knee, San Antonio claimed the win to stay atop the NBA.
Nate Robinson scored 20 points to pace the Bulls while Joakim Noah added seven and 15 rebounds for the home team which faded down the stretch.
Chicago (30-21) has now lost three of four.