Gary Neal added 18 points and Tim Duncan recorded a double-double with 16 points and 11 rebounds for San Antonio, which has won six straight games. The Spurs are now 2-0 on their annual rodeo road trip that spans nine games over three weeks.
"Tony and Tim have been great in this stretch," said Spurs head coach Greg Popovich. "The bench has surprised us all. Those guys are playing really well for us off the bench and that's what is allowing us opportunities to win."
Lou Williams added a spark off the bench with 22 points and Andre Iguodala added 17 points and seven boards as the Sixers dropped to 13-4 at home this season.
San Antonio got back-to-back three-point plays by Tiago Splitter, and then Parker as it quickly turned a five-point third quarter advantage into a 68-57 lead with under two minutes to play.
The Spurs would take a 75-67 lead into the final stanza.
The Sixers looked poised for a comeback as a corner three from Jrue Holiday cut the lead to 83-78, but Neal had an answer as his three-pointer from the wing put the Spurs up 86-78 with just under seven minutes left in regulation.
The Sixers again cut it to five on a Williams three from the top of the key, but Parker drilled a mid-range jumper to put the Spurs ahead 97-90 with 1:26 left and close out the game.
"This is a world championship team and organization," said Sixers head coach Doug Collins. "Pop is a great coach. They string you out. They get you in pick-and-roll and put three-point shooters on the floor. Neal came in and really hurt us tonight."
The Spurs and Sixers exchanged three-pointers early on as Holiday and then Neal knocked down triples to close out the first quarter with the Spurs clinging to a 26-24 advantage.
Thaddeus Young finished a layup in the paint that capped a 10-0 run to pull the Sixers in front, 38-36, with four minutes to play, but the Spurs would regain control, taking a slim 48-45 lead into the locker room.
The Sixers will host the Clippers on Friday, while the Spurs continue their road trip in New Jersey on Saturday...The Spurs had lost four straight in Philadelphia entering the game...San Antonio got to the free throw line 26 times, while Philadelphia managed just 11 trips to the charity stripe...Sixers are now 0-5 when giving up 100 or more...Sixers had season-low 4 steals...Parker's 37 is the most of any opponent vs. Philly this season.