"When you play the top teams in the league, it comes down to the little things," said Pierce, who had 19 points and eight rebounds. "I just thought the last couple of games at home it was 1- or 2-point games. Defensive transition late in the game, covering for one another [defensively], one possession [situations], it's like the playoffs . . .
"One play can kill you. Every possession counts, and we've got to understand that when we play against the top-tier teams like the Spurs and the Lakers."
The little things really began affecting the Celtics after the game was tied at 87 in the fourth quarter.
Spurs forward Tim Duncan (23 points, 13 rebounds) had a 3-point play off an offensive rebound with 3:52 left that pushed Boston behind, 90-87.
"The big play was Tim Duncan's big offensive rebound and a foul for [a 3-point play]," said Celtics guard Rajon Rondo, who had 6 points on 3-of-11 shooting, 16 assists, and 1 turnover in 38 minutes.
Still, the Celtics were able to respond with a 6-0 run capped by a pair of Kevin Garnett jumpers to take a 93-90 lead with 1:36 remaining.
Following a Garnett missed jumper, Matt Bonner nailed a jumper to trim San Antonio's deficit to 93-92 with 45.1 seconds remaining. Garnett missed another jumper with 28 seconds left on the following possession that was rebounded by San Antonio.
Spurs coach Gregg Popovich elected not to call a timeout. After Duncan set a solid screen on Ray Allen, Spurs guard Roger Mason Jr., nailed a wide-open 3-pointer with 20.4 seconds left to push San Antonio ahead, 95-93.
"I was more concerned really about giving up the 3-point shot," Celtics coach Doc Rivers said. "That was more troubling to me than anything."
Popovich credited the Celtics as the reason he didn't call time.
"That's why we didn't call a timeout at the end because they are such a great defensive team," he said. "To have them set their halfcourt defense is probably not the best thing for an offense. We thought if we had everybody in movement we might have a better chance to make a shot and Roger did it."
