Former Masters champion Hideki Matsuyama was disqualified midway through his first round at the Memorial Tournament because of illegal markings on his fairway wood.
He was penalised for breaching rule 4.1a, the use of a non-conforming club.
The PGA Tour’s chief referee Steve Rintoul said a substance that looked like white correction fluid had been applied to the 30-year-old’s club.
The world number 12 was three over when he was disqualified on the 10th tee.
It is the first time in his career that the Japanese player, last year’s winner at Augusta National, has been disqualified.
“Those markings were placed there by his club guy to help with alignment,” Rintoul said.
“Assistance with alignment by placing a small Sharpie mark on the face is certainly allowed, but what was done there was a coating that was not only in the grooves but was very thick along the face, which renders the club non-conforming.”
Matsuyama won the first of his eight PGA Tour titles in 2014 at The Memorial, where the lead is shared by six players after this year’s first round.
Mackenzie Hughes, Davis Riley, Cameron Young, Luke List, Cameron Smith and Kyoung-Hoon Lee are all on five under after starting with a 67 in Jack Nicklaus’ tournament at Muirfield Village in Ohio.
Bryson DeChambeau, trying to regain form after injury in time for the US Open, shot four over but Rory McIlroy enjoyed a better day as he started with a 70.
