Ryan Fox matched the men's major low round with a 62 at Royal Birkdale, finishing Saturday's early action tied for the Open lead at 8 under.
Five birdies in his first eight holes sparked the charge, and Fox stood one birdie from a historic 61 before a closing par left the record at 62.
The 62 made Fox the seventh man to shoot that number in a men's major and the third player to do it this week at Royal Birkdale.
The surge came in another volatile round after Friday featured two 62s that were partly overshadowed by a two-stroke penalty, underscoring how unusually chaotic this Open has become.