Harden was sidelined by a strained left hamstring.
Green made his first five 3-point shots and finished 7 for 10 from behind the arc for the Rockets, who were never behind and led by as many as 28 late in the third quarter.
Eric Gordon added 17 points and six assists to help Houston tune up for its Thursday night showdown with the Golden State Warriors.
Aaron Gordon led the Magic with 16 points after missing his first eight shots. Elfrid Payton and Mario Hezonja added 14 each in Orlando's 12th loss on 13 games.
The Magic (12-27) missed 16 of their first 18 shots and fell behind by 15 points before the end of the first quarter. A scoring burst by Hezonja kept them in the game in the second quarter but they could get no closer than nine.
Capela scored on a layup, a dunk and two free throws during the Rockets' 15-5 spurt at the outset of the second half, turning the game into a rout at 70-46.
Houston shot 44 percent (15 for 34) from 3-point range while Orlando shot 19 percent (6 for 31).
Rockets: The game was only the second missed by Harden in the last four seasons . . . After getting 10 points and five rebounds, Nene left the game with a bruised right knee.
Magic: F Jonathon Simmons left the game in the second quarter with back spasms and did not return.
Rockets: Host Golden State on Wednesday night.
Magic: Host Cleveland on Saturday night.
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