Belinelli hit a huge 3-point shot in the final 2 minutes, during which the Hornets rallied from an 81-76 deficit and the Warriors failed to score.
Belinelli led New Orleans with 23 points in the game. Carl Landry added 14.
Klay Thompson led Golden State with 16. The Warriors, who shot 41.8 percent from the field, have lost nine of their last 10 games.
The Hornets shot 43.7 percent from the field and just 61.3 percent from the free-throw line.