Cameron Davis and Will Zalatoris lost thousands of pounds in prize money after a mix-up at The Sentry tournament in Hawaii.
The pair were playing as partners in the final round and inadvertently hit each other's ball on their third shot on the par 15th hole to incur penalties.
“After realizing their mistake on reaching the green, they returned to playing from the proper position for their third shot — but are now playing their fifth shot instead of their third, in accordance with the Rules of Golf,” the PGA Tour said.
Australian Davis finished 22 under par and took home $410,000 (£328,000) in prize money, but would have received $715,625 (£572,000) had it not been for the two-stroke penalty.
Zalatoris finished the event with a 19-shot lead and won $163,333 (£131,000) instead of $283,200 (£226,000) if he had finished two shots better.
If the duo had continued playing and had not corrected the mistake, they could have been disqualified from the tournament, which is what happened It was won by Japanese Hideki Matsuyama.