Ginobili drove straight to the basket, on the left side of the lane.

As Celtics defenders collapsed towards him, the Spurs guard fired a perfect pass along the baseline to Michael Finley, coming off a Tim Duncan screen to an unguarded spot behind the 3-point line in the right corner.

Finley caught the pass, nailed the 3-pointer and a sellout crowd of 18,581 roared, thinking the Spurs had pulled within two points with time left to complete a comeback.

Referee Benny Adams, however, was blowing his whistle and pointing to the right sideline, indicating Finley's right foot had touched the line as he caught Ginobili's pass.

No basket. Celtics ball.

"Just kind of how the night went," Duncan said. "Everything but the score."

The end of a five-game win streak for the Spurs , now 9-7, was the product of some mind-numbing numbers that resulted from sloppy play and poor execution by an offense that was challenged by one of the NBA's best defenses.

* Nineteen Spurs turnovers, six of them by Duncan, resulted in 19 points for the Celtics.

* Ten missed free throws in 17 attempts at the line eliminated chances to keep Boston's lead from growing to 15.

* Making only two of 16 3-point attempts doomed a comeback effort that somehow kept some drama in the AT&T Center right to the final seconds.

"The game's a 48-minute game and you've got to play for 48, especially against a great team like Boston," Popovich said. "Tonight, we played a quarter, and that's not good enough.

Popovich found no fault with his players' effort, but was perplexed by their lack of precision.

"They persevered all night long, but they were sloppy," he said. "They turned it over, missed free throws, missed some assignments here and there, but against the best team in the league you've got to play for 48. You play other teams that aren't the best and you've still got to play for 48 or it's going to bite you in the butt."

One play, in particular, illustrated the Spurs' lack of focus and vexed their head coach. Boston's Rajon Rondo picked off a simple in-bounds pass from Richard Jefferson that was intended for Tony Parker, racing downcourt for an easy layin that gave the Celtics a 12-point lead early in the third period.

Another defied all logic and told Popovich his team was in for a long night.

Going up for an uncontested rebound after a miss by Boston's Brian Scalabrine, Spurs rookie DeJuan Blair attempted to snatch the rebound with one hand. Somehow, the ball slipped down his arm, off his elbow and caromed into the Celtics' basket.

Official scorekeepers had to check a TV replay to find a Celtics player close enough to the play to credit Marquis Daniels with a basket, by NBA rule, when he didn't even touch the ball. The play overshadowed Blair's 18-point, 11-rebound night.

"I should have grabbed it with two (hands)," Blair said. "It never happened to me before.

"Wow. That's what I get."

What the Spurs got was a loss that stung more for the way it happened.