Duncan scored 21 points, rookie George Hill added 19 points and 11 rebounds, and the Spurs beat the Bulls 98-88 on Wednesday night.
"I think fans see that he scored 15 points or something like that, I don't even remember," Spurs coach Gregg Popovich said of Hill. "He got 11 rebounds. He got some steals, and he made some defensive plays that will go unnoticed, but help teams win. He plays an all-around game and does a great job for us."
The Spurs have won six of their last seven games and are 8-6. San Antonio reached .500 at home (4-4) for the first time this season, and it's the 10th straight game the Spurs have limited their opposition to less than 100 points.
Duncan took only two shots in the second half after finishing the first half 7-of-10 from the floor for 18 points.
Hill, the 26th overall draft pick out of IUPUI, played the entire fourth quarter and was 4-of-9 from the floor. He made all four free throws, grabbed five rebounds and had a pair of assists in his first career double-double.
"Any time you have your first double-double, I guess it's big," he said. "I really didn't know until someone said 'Hey, you have your first career double-double.' I wasn't really focused on that. I just like to win basketball games. That was the only thing I was looking at."
"Their second team came out there and played harder than their first team," Bulls forward Drew Gooden said. "I think we stood on our heels when we saw Tim Duncan and Manu Ginobili were out. But Hill and Kurt Thomas killed us on the pick-and-roll."
Ben Gordon led Chicago with 23 points. Gooden added 20.
The Bulls (7-9) have lost four of six since starting a seven-game road trip on Nov. 18. The trip ends Sunday in Philadelphia.
The game marked a return to San Antonio for former Spurs player Vinny Del Negro, now in his first season as coach of the Bulls.
With Gordon and Gooden opening the second half by making their first eight shots combined, the Bulls were ahead by nine points midway through the third quarter.
The Spurs got a pair of layups by Ginobili and two 3-pointers by Udoka. Fellow reserve Matt Bonner also hit one.
Udoka's second 3-pointer broke a tie and gave the Spurs a 72-69 lead with 2:30 left in the third quarter. It was set up by Ginobili's drive and slingshot pass. Ginobili scored 15 points and had four assists in 18 minutes.
San Antonio never trailed again. The Spurs opened the fourth quarter by outscoring Chicago 13-2 and led by as many as 16 points with just more than four minutes to go.
Most of Gordon's points came on the fast break. The Bulls were up 13-5 in fast-break points through the third quarter, until the Spurs limited the fast-break opportunities by hitting some key baskets.
"We were going pretty good on the fast break for a while, but they limited that by taking care of the ball and hitting 3s," Gordon said. "It put us in a pretty bad position."
Ginobili, who played for the first time this season Monday in Memphis after recovering from left ankle surgery, made his home debut and teamed with Duncan to give the Spurs an early boost. Duncan and Ginobili combined to go 7-of-11 from the floor for 17 of the team's 25 first-quarter points.
San Antonio led 36-30 with six minutes before halftime before Gordon and the rest of the Bulls guards evened the game.
Lindsey Hunter started it with a 3-pointer off Derrick Rose's pass. Rose hit a pair of mid-range jumpers and Gordon scored twice on the fast break. The second one, a running 10-footer with 1.9 seconds left, tied the game at 45 and gave Gordon eight points in the second quarter.
Del Negro, who was the starting shooting guard for the Spurs when the team went 301-191 and won two division titles from 1992-98, received a warm ovation from the San Antonio crowd when he was introduced as Bulls coach before the game. ... The Bulls are 2-7 on the road. ... Roger Mason was 15-of-22 from 3-point territory the last three games before shooting 2-of-5 from the arc Wednesday. ... Hill has scored 20 or more points three of the past four games before his 19-point effort Wednesday. ... The Bulls are 3-18 against San Antonio since the 1998-99 season, including 1-9 in San Antonio.