Ime Udoka added a season-high 18 points and four other Spurs scored in double digits to give San Antonio its second straight victory.
Kobe Bryant led the Lakers with 29 points and 12 rebounds, and Ronny Turiaf scored 14 points. Sasha Vujacic and Lamar Odom added 11 points apiece.
The Spurs broke open the game in the third quarter, looking like a different team after a less-than-stellar first half.
They started with a 14-0 run that included six points from Duncan, grabbing a 59-54 lead with 5:39 left. Tied at 61 with 4:18 to play, San Antonio closed the quarter - and took the lead for good - by outscoring the Lakers 15-5.
The Spurs scored nine of those points in a crowd-pleasing burst over the final 38 seconds of the period. Udoka, in his first season with the Spurs, hit two baskets, then sank a 3-pointer with 38 seconds left.
Then guard Brent Barry, who made his first start of the season, took over, hitting consecutive 3s in the last 7 seconds of the period to give the Spurs a 76-66 lead heading into the fourth.
The Lakers got within six points midway through the fourth, but the Spurs, moving the ball until they could find an opening, pushed their lead to 97-84 with 3:47 left off of Udoka’s three-point play and Manu Ginobili’s 3 from the top of the arc.
The Lakers never threatened after that.
Before their second-half demise, the Lakers held a 54-45 lead at halftime. The Spurs, looking disorganized, had 17 rebounds - including 10 from Duncan - in the first half to the Lakers’ 27. Los Angeles outscored San Antonio 32-8 in the paint.
The Lakers took their biggest lead of the first half off a 14-4 run that put them up 46-33 with 5:13 to play in the half.
