Duncan, sporting a new look with his head shaved clean, also had 13 rebounds for his third straight double-double.
The Spurs (11-8) entered the game scoring 93.5 points per contest. But the Spurs scored 108 while winning Thursday night at Denver, and their point total against Golden State was a season high for a regulation game.
Michael Finley and Tony Parker added 17 points each for the Spurs.
Duncan and Finley were both 7-of-10 from the floor, and Parker was 8-of-14 to help the Spurs shoot 55 percent for the game. They shot 61 percent through three quarters.
Golden State's nine-game losing streak is the longest current streak in the NBA. It's the first time the Warriors (5-15) have lost that many in a row since March 27-April 11, 2006. The Warriors shot 37 percent.
Golden State took the direct route to another loss. The Warriors allowed the Spurs to score on 11 of their first 12 possessions. Six of those came on layups, including two by Matt Bonner, who added 14 points.
The Spurs' biggest lead was 41 points in the fourth quarter.
It got so bad for Golden State that Stephen Jackson took the rest of the night off to rest a bothersome arm injury with the Warriors trailing 51-34 with 6:09 left in the first half. Warriors officials announced the injury as a sprained left hand.
San Antonio has scored 30 or more points in the opening two quarters of two consecutive games. The Spurs scored 30 and 31 points in the first two quarters for a season-high 61 points in the first half during the 108-91 victory Thursday at Denver.
Against the Warriors, San Antonio had 35 in the first quarter and 30 in the second quarter for another season-high first half. The 35-point first quarter was a point shy of a season high.
To add to Golden State's misery, the Spurs scored 39 in the third quarter.
While the Warriors looked like themselves on defense — they give up a league-worst 111.4 points per game — their typical offensive punch stayed behind in Houston with the 131-112 loss to the Rockets on Friday. It was the third straight game the Warriors had scored more than 110 points.
But in the first quarter against the Spurs, Golden State 6-of-22 from the floor and was outscored in the paint 18-2.