Eloy Teruel thought he had the seventh stage of the Tour of California wrapped up when he raised his hands in victory a full lap before the race was due to end. You can hear the PA announcer roaring "No, no no, no!" to Teruel but he realises too late. He finished 56th. An absolute shambles.
https://www.youtube.com/watch?v=7NDYpOJgyZQ
H/T: Tommie2cans