The Bucks had lost four of their last five in San Antonio before Sunday's game.
"We beat them last year a couple of times. I know that word was floating around that they were motivated to put an end to that," Bucks coach Larry Krystkowiak said. "It just didn't appear as though we were ready for a top-level opponent like the Spurs."
The Spurs improved to 6-1, while the Bucks fell to 2-4.
"We've played very well against the Spurs since I've been here," said Andrew Bogut, who scored 10 points for Milwaukee. "Tonight, we just didn't bring it from the start."
The Spurs were up 65-38 at the half, and with the Spurs shooting about 60 percent and the Bucks around 40 percent, it only got worse for Milwaukee in the third quarter. Ginobili hit his third 3 of the game, and two free throws apiece from Parker and Francisco Elson gave the Spurs a 40-point cushion with 2:59 left in the period.
"I just started making a couple of shots," Ginobili said. "We moved the ball well. I guess they didn't do really good defense, so making that extra pass we were able to take a lot of wide-open shots."
But Williams and Redd led a 10-0 run for the Bucks in the final 2½ minutes of the quarter to reduce the deficit to 91-61 with 12 minutes to play.
Popovich took out all of his starters for the beginning of the fourth, and the Bucks were able to take advantage -- to a point. Bobby Simmons hit two 3s over in a 1:10 span to help cut the Spurs' lead to 97-72 with 9:08 left.
The Bucks got within 23 points several times in the fourth, but no closer.
"We need to be tougher, we need to protect what we're calling our house ... the paint," Krystkowiak said. The Spurs had a 50-36 advantage in the paint.
The Spurs took the lead for good when Finley's 3 with 8:06 left in the first broke a 10-all tie.
The Spurs went up 36-24 at the end of the first quarter as Ginobili hit a 3-pointer at the buzzer. He scored seven points in just over two minutes in the opening period.
"It's good to see a player like that not complaining that he's coming off the bench," Bogut said. "He obviously could be a starter for any other team in the NBA."
Ginobili continued to produce in the second, scoring 11 points, including another 3-pointer. His fast-break layup with 56.1 seconds to go in the half put the Spurs up 64-36, their biggest lead of the half.
Williams led the Bucks with 10 points at the half.
Sunday's game was the first of four that the Spurs will use this season to celebrate the franchise's 35th anniversary. ... The Spurs outscored the Bucks 29-14 in the second quarter. ... The Spurs hit 8 of 20 3-point attempts. ... San Antonio shot 39-of-70 (56 percent) from the field. The Bucks finished 34-of-82 (42 percent.) ... The Spurs' bench outscored Milwaukee's 59-30.