BOSTON -- The San Antonio Spurs rested up before playing the defending champions, and it paid off.
"It's hard for the oldest team in the NBA to feel fresh," coach Gregg Popovich said Sunday after the Spurs scored 11 straight points in the final 45 seconds to turn a one-point deficit into a 105-99 victory over the Boston Celtics.
"It was a beautiful win for us, against the NBA champions and on the road makes it even sweeter."
Roger Mason pulled up and leaned into a 3-pointer with 20.4 seconds left to give San Antonio the lead, then hit a pair of free throws after Manu Ginobili hit four as the Spurs pulled away from the Celtics. Tim Duncan scored 23 points with 13 rebounds and Matt Bonner had 23 points -- the second-most in his career -- including 3-of-6 from 3-point range.
The Spurs won for the ninth time in 11 games.
Ginobili scored 19 points off the bench, playing more than 31 minutes after sitting out Tuesday's game against Denver with a bruised hip. Duncan, who had not missed a game since 2007, also sat out the Nuggets game, as did Michael Finley and Tony Parker while the Spurs try to pace themselves over an eight-game, three-week road trip.
"If I would have played in Denver, I wouldn't have been this fresh for sure," Ginobili said. "It was very important for us to get rest a couple of days."
Kevin Garnett scored 26 points with 12 rebounds, Paul Pierce had 19 and eight and Rajon Rondo had 16 assists for Boston. It was the second loss in three games for the Celtics, who lost to the Los Angeles Lakers on Thursday in an NBA Finals rematch to snap a 12-game win streak.
Boston embarks on a six-game road trip, interrupted by the All-Star break, before returning home at the end of the month.
"We've got a tough task in front of us, going on the road for the next couple of weeks, and we've got to make up some ground," Pierce said. "We have our work cut out for us. This is a big road trip for us."
Duncan converted a three-point play to give the Spurs a 90-87 lead before Ray Allen's basket cut it to one point and Garnett hit a pair of jumpers to give Boston a 93-90 lead with 1:36 to play. But Bonner hit a jumper from the foul line and Garnett missed, then Mason hit his 3 to make it 95-93.
The Celtics were inbounding the ball when Ginobili stole the pass and drew a clear-path foul, giving him two shots and the Spurs the ball. San Antonio extended its lead to 101-93 before Eddie House and Garnett hit 3-pointers to help cut the deficit to three points.
The Spurs scored the last five points of the first half to open a 60-52 lead, but the Celtics opened the second with 12 straight points to retake the lead.
Boston is 24-4 at home, with all four losses coming against the Western Conference. ... The Celtics are in a stretch where they play three of the top four teams in the Western Conference in four games, starting with the conference-leading Lakers on Thursday and, after the Knicks on Friday, No. 2 San Antonio and No. 4 New Orleans on Wednesday. ... Finley had played 284 straight games before sitting out on Tuesday.