Three games followed, with the 33-year-old’s good opening looking set to continue with a powerful drive from the fifth tee. However, incredibly, McIlroy’s speeding shot was prematurely grounded when it bounced off a stone in the middle of the fairway. Shaped like tiny tombstones and known as March Stones, they mark the ends of the original march, which dates back to the 15th century. Despite the stone’s best effort, McIlroy composed himself superbly to bogey the par-5 hole, before rattling off two more in a row to sit 4-under after just seven holes. Speaking to reporters after his round, the four-time major champion admitted that while he hadn’t noticed the stone’s effect on his drive, he had been talking to his instructor Harry Diamond about the prospect of an unlucky golfer being forced to play a shot. from behind one. “I said to Harry, some poor guy is going to have his ball end up right behind it today because it’s right on the fairway and I don’t think you’re going to get one drop,” McIlroy said. There was also a slight poke at round mates Collin Morikawa and Xander Schauffele, who threw the fifth without any intervention. “I think I still got it past the other two,” laughed McIlroy, reflecting on his next shot. A bogey at the 13th provided the only blemish on the Northern Irishman’s score as a closing birdie on the final hole saw the 2014 Champion close with a 6-under 66, leaving him two shots behind clubhouse leader Cameron Young. “Fantastic start,” McIlroy said. “What you hope happens when you start your week. “I did what you had to do around St Andrews… It’s another good start to a big one, three in a row for me now. I’m looking forward to the next few days.” However, while the Claret Jug remains very visible to McIlroy, one of his few stray drives was not seen by any unlucky onlookers. Charlie Kane, a PGA Tour official, tweeted that he suffered a broken arm after the golfer’s ball hit his knuckle. Accompanying photos showed painful bruising, but they concluded they showed Kane walking back onto the course smiling, albeit wearing a sling. “Shout ahead. I didn’t heed the warning,” he wrote. McIlroy is scheduled to start his second round at 2:59 p.m. BST (9:59 a.m. ET) on Friday.