"(Duncan) did a great job, especially with the way he was feeling yesterday," said Manu Ginobili, who missed a game Tuesday night because of the bug.
"When I was first feeling bad, the following day I was feeling terrible. So I was surprised. I didn't expect him to contribute much."
Duncan's playing status wasn't certain until about 20 minutes before the game. At least five other Spurs have been affected by the bug.
"I thought Timmy did a great job coming off the flu he had yesterday to come back and play like he did," Spurs coach Gregg Popovich said. "I didn't think he would play."
The Hawks have lost seven straight and 11 of 12 to drop to 9-20. The Hawks have lost nine straight in San Antonio dating to Feb. 15, 1997.
The Spurs led 67-61 after three quarters, and opened the fourth with a 10-0 run.
San Antonio outscored the Hawks 14-2 on the fast break in the fourth quarter.
"We were feeling pretty good about ourselves at the end of the third period down by only six points," Hawks coach Mike Woodson said. "We need a lot of help offensively. This team is fighting a lack of chemistry."
San Antonio outrebounded Atlanta 55-43, including a 14-8 advantage in offensive rebounds.
The Hawks committed only three more turnovers than the Spurs, but San Antonio scored 27 points off the Hawks' 21 mistakes compared to the nine points Atlanta converted off turnovers.
The Spurs beat Atlanta 23-6 on the fast break, which led to a 54-26 advantage San Antonio had scoring points in the paint.
It was Parker's third straight game scoring more than 20 points and fourth in his last five.
Led by Ginobili's 8-of-10 performance from the floor, the Duncan-Ginobili-Parker trio combined to shoot 25-of-41. The rest of the team was 12-of-39.
"It was a great all-around effort," Popovich said.
- Atlanta was 7-22 after 29 games in 2005-06.
- F Robert Horry got his second start of the season for the Spurs, both coming in the past two games because of C Francisco Elson's right torn rotator cuff injury.
- Spurs F Matt Bonner had a season-high seven offensive rebounds.