Seven (7) hours. Between William Muldoon and William Miller in the original Madison Square Garden on 3-23-1880. Match started at 8:47 and lasted until 4:00 AM. Muldoon also had a match the next year with Clarence Whistler which lasted from 8:40 to around 3:30 AM. They were allowed ten minute breaks after each hour. The owner of the venue turned off the gaslights which ended the match as the men got ready for the seventh hour. In modern times Bruno Sammartino wrestled Pedro Morales is a 65:05 draw in 1972.