Terrence Jones got Houston back into the game in the third quarter and Harden finished off the Pelicans in the fourth. They finished with 25 and 26 respectively.
Dwight Howard pitched in with a double-double of 12 points and 11 rebounds.
The Pelicans got big performances from Eric Gordon and Anthony Davis, but couldn't make the big plays down the stretch to halt Houston's momentum.
Gordon scored a season-high 35 and Davis added 24.