It's the first time this season that the Spurs (29-6), who still have the best record in the NBA, have lost back-to-back games.
Ray Allen scored 31 for Eastern Conference-leading Boston (27-7), but he missed a pair of free throws with 8.1 seconds left, leaving the Celtics up by two. After a timeout, Manu Ginobili worked down the clock and put up a shot that was blocked by Paul Pierce and pulled down by Rondo for his 10th rebound.
Glen "Big Baby" Davis had 23 points — one short of a career high — playing in place of the injured Kevin Garnett. Rondo's 22 assists were the second-most in his career; he had 24 in an Oct. 29 game against the New York Knicks that was his only other triple-double this season. His six steals were a season-high and one off his career-high.
Ginobili had 24 points and eight rebounds for San Antonio. Tim Duncan and Tony Parker had 18 points apiece for the Spurs, who were coming off a 128-115 loss to the Knicks in New York on Tuesday in which coach Gregg Popovich pulled his three stars with more than three minutes left, down by just 11.
They needed the extra rest in a game against Boston that went down to the wire.
San Antonio took a 70-67 lead on Duncan's hook shot with 3:37 left in the third quarter, but they did not score again until George Hill beat the buzzer with a bank shot. In the meantime, Boston scored 10 straight points, including a 3-pointer from Pierce to tie it and his slamming, swinging-from-the-rim dunk that made it 77-70.
But the Spurs quickly erased the deficit, thanks in part to Ginobili's back-to-back 3-pointers that cut the deficit to 86-85 with 7:21 left. It was 96-all when Rondo grabbed his ninth rebound and worked the ball down to Marquis Daniels for a layup, then Pierce found Allen for a 3-pointer that made it 101-96 with 97 seconds left.
Davis drew an offensive foul on Richard Jefferson as he drove, out of control, down the baseline, then Rondo drove into the lane and floated one over Duncan to give Boston a 103-96 lead with 66 seconds left. Allen stripped the ball away from Hill and went in for the layup and Boston's biggest lead of the game.
But Ginobili hit a 3-pointer, Parker drove for a layup and then Jefferson hit a pair of free throws to cut the Spurs' deficit to two points. With Boston still leading 105-103, Pierce missed a jumper but Nate Robinson pulled down the rebound and got the ball to Allen, who was fouled.
He missed both free throws.
Notes
The Spurs waived backup swingman Ime Udoka during the day. Udoka played sparingly in 20 games after being signed in November. It was his second stint with the Spurs after spending two seasons in San Antonio following the team's last championship in 2007. … San Antonio rookie James Anderson is expected back soon after missing the last two months with a stress fracture in his foot. … Jermaine O'Neal fouled out with 3:13 left. … Pierce was called for a technical foul with 4:55 left for complaining about a foul non-call. That helped the Spurs tie it at 90…. Boston is 3-1 since Garnett went out with a right calf injury.