RORY McILROY SUFFERED a two-stroke penalty for a rules infraction as he endured a nightmare end to his opening round at the AT&T Pebble Beach Pro-Am.

The Holywood native was penalised for an improper drop on the par-5 seventh, his 16th as he started the day at Spyglass on the back nine, which meant a bogey became a triple.

McIlroy went through his last four holes five-over par to finish one-under after carding bogeys either side of the penalty.

McIlroy had been in the lead after 10 holes on six-under but finished tied in 39th place, well adrift of leader Patrick Cantlay on eight-under par.

“So I took an unplayable on 7 and I took it back on-line,” McIlroy said on PGATour.com.

“Then unbeknownst to me, the rule changed in January 2023 where you used to be able to come back on-line, take a club length either side. That was changed in 2019 to be able to do that.

“I wasn’t aware that that rule was changed again in 2023, so I took a drop thinking of the 2019 rules when everything was sort of changed, not knowing that the rule was changed again in 2023, so I got a two-stroke penalty there.”