Marco Belinelli's layup with 1.5 seconds remaining sent the Hornets past the Warriors, 83-81, on Tuesday.
Golden State was up 81-76 with two minutes to play, but didn't score again and a three-pointer from Belinelli and a layup from Greivis Vasquez preceded the Italian's game-winner.
Belinelli finished with a game-high 23 points and Carl Landry added 14 for the Hornets, who will close their season in Houston on Thursday.
Klay Thompson scored 16 to pace Golden State, which has lost nine of its last 10 games and will wrap up the season against San Antonio on Thursday.
"I know where Klay Thompson fits," Warriors coach Mark Jackson said of his team's potential rotations next season. "Other than that, it's based on improvements we make as a team, whether it be through the draft or free agency or any other avenue we take."
Golden State scored six straight points late in the fourth, getting two jumpers from Charles Jenkins and a dunk from Mickell Gladness to go up 79-72 with just under three minutes to go.
It was the largest lead of the quarter for the Warriors, but the Hornets closed the game with an 11-2 spurt to capture the win.
The game was consistently tight throughout. It was tied, 43-43, at the half and Golden State held a 64-61 lead entering the fourth after getting seven points from Thompson in the third.
New Orleans won the season-series, 2-1...The Warriors have already shut down guard Stephen Curry (sprained right ankle), center Andrew Bogut (broken left ankle) and forward David Lee (groin, hip) for the rest of the season.