The Spurs (43-13) never trailed, while the Magic (21-37) lost for the fifth time in six games.
San Antonio, which owns the second-best record in the NBA behind the Golden State Warriors, did not play its starters -- except for center Dewayne Dedmon -- in the fourth quarter.
Dedmon, who played last season for the Magic, had 10 points and a team-high 11 rebounds. Reserve Patty Mills scored 13 points and hit three of his seven 3-point attempts.
Spurs veteran Manu Ginobili, who had two points, left limping early in the fourth quarter with a twisted left ankle.
Center Nikola Vucevic led the Magic with 16 points and 10 rebounds. Forwards Aaron Gordon and Jeff Green each scored 11 points. Evan Fournier had nine points.
The Magic traded starting power forward Serge Ibaka to the Toronto Raptors for swingman Terrence Ross on Tuesday, but Ross was not cleared to play.
The Spurs dominated around the basket with a 50-33 rebound advantage. They scored 42 points from inside the lane and led by as many as 30 points late in the game. The Magic never got closer than 20 points in the fourth quarter. The Spurs also shot 47.2 percent from the field, while the Magic shot just 39.5 percent.
The Magic made an 11-0 run midway in the third period -- including a 3-pointer by Elfrid Payton -- when they cut the deficit to 12 points. Leonard scored seven points in the first three minutes of the second half, squelching any thoughts of a serious Magic comeback.
The Spurs led 54-37 at intermission, capitalizing on the early, sloppy play of the Magic, who had 14 turnovers in the first two periods.
Leonard had 15 points and Aldridge 13 in the first half when the Spurs led by as many as 25. The Spurs scored first and never trailed when they hit 23 of their 46 shots.
Aldridge did as he pleased in the first quarter, hitting six of his seven shots. He was guarded by Green, who moved into the starting lineup Wednesday when the Magic traded power forward Serge Ibaka the day before.
Vucevic had six points and seven rebounds in the first half. Green and C.J. Watson each had seven points before intermission.
NOTES: Magic coach Frank Vogel said the trade that sent PF Serge Ibaka to Toronto for G/F Terrence Ross and a 2017 first-round draft pick would change his team's style of play. "We're making a movement toward playing smaller," Vogel said. "We tried to play a lot of big lineups before, and it hurt us at both ends." ... The Magic beat the Spurs earlier in San Antonio, a highlight of Orlando's woeful season. ... The Spurs came into Wednesday night shooting 40.4 percent from 3-point range, best in the NBA, and were allowing only 98.7 points per game, second best in the league. ... The Magic's embattled GM Rob Hennigan, who has been under fire recently for questionable roster moves, gave this assessment when discussing his trade of Ibaka: "As we've watched our team play over the course of the season, clearly something's amiss. Something is not clicking," he said.