ST ANDREWS, Scotland — The first prize of 1.15 million pounds ($1.79 million) will be shared out among the professionals if an amateur wins the British Open later on Monday.
"Amateur players are not eligible to win prize money," the Royal and Ancient organisers said on their official Twitter account.
"Should an amateur win #TheOpen first-place money will be distributed proportionately among the professional players who have made the cut."
Irish amateur Paul Dunne leads the way on 12 under par alongside South African Louis Oosthuizen and Jason Day of Australia.
Dunne and Oosthuizen tee-off together in the day's final pairing at 1430 local time.