"Titane", a wildly imaginative film about a serial killer by French director Julia Ducournau, won the top Palme d'Or prize at the Cannes Film Festival on Saturday - as revealed by jury head Spike Lee ahead of time.
Ducournau, 37, became only the second woman to win the top award at Cannes.
In a moment of confusion when asked in French to reveal what one of the prizes was, the US film director read off a card and prematurely announced the best movie winner.
"No excuses, I messed up," Lee told a news conference after the event. "I'm a big sports fan, it's like the guy at the end of the game at the foul line, he misses a free throw, or the guy misses a kick."
It was not the first blooper moment at an awards ceremony: at the 2017 Oscars, musical La La Land was incorrectly announced as best movie, instead of Moonlight.
Ducournau, 37, became only the second woman to win the top award at Cannes.
Described as a "body horror" movie and based around a character with a titanium plate in her head, the film impressed with its energy.
Ducournau had previously found critical success with Raw in 2016. The only previous female winner of Cannes' top award was Jane Campion who shared the prize in 1993 for The Piano.
The world's biggest film festival returned to the French Riviera after a 2020 hiatus due to the coronavirus pandemic in one of the most unpredictable contests in years.