Mason, Antonio McDyess and Theo Ratliff each scored in double figures as the Spurs beat Los Angeles for the 14th straight time and second in eight days.
"That's one of our strengths," Mason said. "We have a deep team, and anytime the starters give us a good edge, we want to come out there and extend the lead when we can."
Parker, who was 7 of 11 from the field, had eight points in a decisive third-quarter run as the Spurs extended an 11-point halftime lead to 21 entering the fourth.
Mason finished with 12 points, including 10 in a 9:40 stretch of the second quarter, as San Antonio's reserves outscored their Los Angeles counterparts 41-27.
"Oh, man, that was tough," Clippers guard Baron Davis said. "We were doing a good job by staying in the game, staying close. You know, that bench came in and really made an impact."
For the first time since Nov. 19, that bench group included McDyess, replaced in the Spurs' starting lineup by rookie DeJuan Blair. McDyess totaled 10 points and six rebounds.
"It really doesn't matter where they put me, but tonight I was just able to get shots and get my rhythm real early," McDyess said.
Even Ratliff, a 15-year veteran who has played in 12 of the Spurs' 25 games, got into the act, scoring 10 points and grabbing seven rebounds.
Duncan, who played just 16 minutes, finished with eight points and six rebounds.
"I had a little bit [of a post move] back in the day," Ratliff said. "I have just been watching Tim doing his little running hooks and getting his mid-range game together. You're never too old to learn.
"I've been a starter, I've been an All-Star and all of those things. I've learned from the older guys that have been around me," he added. "They have always stayed ready, no matter."
The Spurs, who put seven players in double figures, have won 14 straight meetings against the Clippers in San Antonio.
Chris Kaman had 23 points and 15 rebounds to lead the Clippers.
"It's the story of our season, as far as towards the end of the game, not being able to finish," Kaman said. "We've had some games where we played well. Tonight wasn't one of them. The Spurs are a good team. They have veterans that know how to play the game."
The Spurs took command with a 15-2 run to end the first. Keith Bogans started it with a pair of 3-pointers, and McDyess capped it with a 17-foot baseline jumper at the buzzer.
Kaman and Eric Gordon kept the Clippers competitive in the second period. Gordon's back-to-back 3-pointers closed the Spurs' lead to 39-35, and Kaman had eight points and seven rebounds in the quarter, giving him 15 and nine for the half.
But San Antonio regained most of the 14-point lead it carried into the period. Mason scored 10 points and Parker capped an 11-point half with a 17-foot jumper with 28.5 seconds remaining that gave the Spurs a 57-46 edge at the break.
Los Angeles started strong in the third period as well but drew no closer than 59-52 before the Spurs broke the game open. San Antonio closed the quarter on a 17-4 run, then scored the first four points in the fourth.
Rasual Butler had 18 points off the bench for the Clippers. Davis totaled 11 points and six assists.
Kaman had a double-double a minute into the third quarter. ... Blair had eight points and six boards for the Spurs.