After claiming his 21st career PGA Tour win last week in Canada, McIlroy took a shot at Greg Norman, the front man for the Saudi-funded LIV series, by saying he had "one more than someone else" and that it gave him extra incentive.

But McIlroy, who has gone nearly eight years since winning the last of his four major titles, said he did not set out looking to make a statement with his clubs.

"Not really. It's been eight years since I won a major, and I just want to get my hands on one again," McIlroy said after a three-under-par 67 gave him a share of the early clubhouse lead before Canadian Adam Hadwin finished Thursday as the solo man at the top on four-under.

While McIlroy enjoyed a solid start to the year's third major, it was not all smooth sailing as he needed to dig deep to avoid falling apart at the fifth hole where his tee shot came to a rest in the tall grass on the lip of a bunker.

McIlroy chunked his next shot 14 yards into another bunker, causing him to twice slam his club into the sand in frustration, but he managed to save par.

"You're going to encounter things at a U.S. Open, whether they be lies or stuff like that, that you just don't really encounter any other week," said McIlroy.

RIGHT: Defending champion Jon Rahm got off to a solid start at The Country Club. PHOTO: USGA.

Jon Rahm had a solid start to his U.S. Open title defence but it was not without drama as he needed two balls to finish his closing hole when two kids felt his initial one would make for a nice souvenir.

Rahm's tee shot at the par-4 18th sailed way left and when he got to where the ball was marked it was nowhere to be found as some onlookers figured it was better than anything they could buy from the merchandise tent that lines part of the hole.

"Somebody – I'm pretty sure I know who it was. I recognised the two kids that were running the opposite way with a smile on their face," a laughing Rahm told reporters. "I am 100 percent sure I saw the two kids that stole it."

"It's been eight years since I won a major, and I just want to get my hands on one again." - Rory McIlroy.

Rahm proved unflappable from the incident and was allowed to drop another ball and from there got to take another drop since a grandstand was in his way.

The Spanish world No.2 then stuck his approach shot to 21 feet and went on to drain the birdie putt for a one-under-par 69 that left him three shots back of Hadwin.