There was a French golfer who took a 7 or 8 on the last hole of the British open to lose.
Jean Van de Velde. 1999. Triple bogey 7. Most agonizing and ridiculous defeat I ever watched live (on TV).
No. Jean Van de Velde royally choked on the 18th but stayed composed enough to get into a playoff where he then lost.
Jean Van de Velde.... He had a three-shot lead standing on the 18th tee. A double-bogey and he would still win. He takes a triple-bogey seven to fall into a tie and loses in a playoff.