The Spurs blew a 17-point lead in the first half before rallying late in the fourth to win again without guard Manu Ginobili. Ginobili is still out with a strained left hamstring.
Evan Turner led the Sixers with 18 points and 12 rebounds. The Sixers lost for the seventh time in nine games. Andrew Bynum, out all season with knee injured knees, said before the game he remained on target to return around the All-Star break.
The Sixers could use him. Without their best player, they've slumped to seven games under .500.
Without Ginobili for the fourth straight game, the Spurs got clutch baskets down the stretch to win their NBA-high 15th road game.
After a miserable first half, the Sixers turned to Spencer Hawes and Nick Young off the bench to come back. The Sixers erased the early 17-point hole with three straight big baskets in the fourth.
Royal Ivey pulled them within two, Turner's 14-footer tied it at 73-all and Hawes put them ahead for the first time in the game with a 17-footer that made it 75-73.
Thaddeus Young's short jumper put the crowd of 15,346 on their feet and stirred up the "Defense!" chant for the first time all game.
Nick Young's 3-pointer and long jumper gave the Sixers a seven-point lead.
But then the sloppy play took hold. Easy missed shots. Turnovers. Duncan blocked Jrue Holiday's layup.
The Spurs got it together. Kawhi Leonard dunked off a turnover, then buried a 3 off a defensive board to tie it 88-all. Duncan's jumper made it 84-82 and Parker swished one the next time down. Danny Green's steal ended the threat and the Spurs escaped.
Led by Duncan, the Spurs took control of this one early and raced to a 17-point lead in the second quarter.
At last in the third, the Sixers came ready to play, showing the sharp shooting touch that abandoned them in the first half. Hawes, who scored 16, buried a 3 as part of an 8-0 run that sliced the gap down to four. Thaddeus Young, however, missed two free throws that would have inched the Sixers closer.
As they do, the Spurs took advantage of the missed opportunities from the line. Parker pushed them back with a jumper and Kawhi Leonard's thunderous dunk quickly made it 61-49.
They just couldn't put away the Sixers that easily. Maybe the outcome would have been different with Bynum.
Bynum, their big offseason acquisition, again expressed optimism he'd finally be ready to play around next month's All-Star game. Bynum has sat out the season because of bone bruises on both his knees. He practiced jump shots with the Sixers at the morning's shootaround and insisted he was pain free.
Bynum, a free agent at the end of the year, has no intention of rushing back. There's still plenty he has to work on before he's cleared.
"It's going to be defensive slides, cutting, running full speed and stopping, backpedaling, jumping," he said. "Explosive stuff."
Bynum wasn't the only reason the Sixers' locker room was buzzing before the game. Former great Charles Barkley - his retired No. 34 hangs in the rafters - called the game for TNT and was a pregame visitor. Barkley received a huge standing ovation when the Sixers aired a video tribute to him.
NOTES: The Spurs won for the 14th time in 17 games. ... The Spurs had averaged 98.0 points in their previous 10 road games. ... The Spurs were 19 of 26 from the free throw line; the 76ers 7 of 11.