Phil Mickelson walks off the course after finishing the 18th hole during the third round of the US Open on Saturday. Photo: Julio Cortez/AP

SOUTHAMPTON, New York – Phil Mickelson hit a moving ball on the 13th green in what he said was a deliberate action to “take advantage of the rules” during the third round of the US Open at Shinnecock Hills on Saturday.

The astonishing moment occurred after the five-time major champion missed the hole with a short putt, and his ball kept trickling and trickling down the hill.

He trotted after it and when the ball was about 15 feet beyond the hole, and still trickling, he hit it back towards the cup.

Mickelson said he knew the action would bring a two-shot penalty, and that he had hit the ball to prevent it from rolling off the green.

“I didn’t feel like going back and forth,” he said. “It’s meant to take advantage of the rules as best you can. In that situation, I was just going back and forth. I would gladly take the two shots over continuing that display.

“I don’t mean any disrespect, and if that’s the way people took it, I apologise to them. I took the two-shot penalty and moved on. There’s not much else to say.”

Hitting a moving ball incurs a two-stroke penalty, and Mickelson was assessed with a 10 at the par-four hole.

He could have been disqualified, however, had rules officials deemed it a serious breach of another rule that states “a player must not take an action with the intent to influence the movement of a ball in play”.

But US Golf Association rules chief John Bodenhamer said Mickelson’s breach did not reach such a level.

Andrew Johnson, who was paired with Mickelson, was stunned by the incident and broke into laughter, prompting Mickelson to also grin as the pair walked off the green.

“I’ve never seen anything like it. It’s something you might see on your home course with your mates. It was just a moment of madness, but nothing disrespectful,” said Johnson.

In contrast to Mickelson’s comments, Johnson concluded that the American had just snapped.

“I think it’s just one of them moments when you’re not thinking about it, it just happens and he did it,” said the burly Englishman, whose nickname is ‘Beef’.

“I said ‘That’s one of the strangest things I’ve ever seen. Sorry, I have to laugh at this.’ He just laughed with me. If you don’t laugh, you’ll end up going insane.”

The incident on Mickelson’s 48th birthday brought to mind a similar episode by John Daly at the 1999 US Open at Pinehurst No. 2.

Daly, however, already had a reputation for being unpredictable, whereas Mickelson’s reputation as American golf’s golden man has been cultivated over almost three decades of exemplary behaviour on the course.

Fox television analysts were stunned. “John Daly’s reputation took a hit after what he did at Pinehurst in ’99, and I fear it will be the same for Phil,” said former US Golf Association executive director David Fay.

Major champions Curtis Strange and Paul Azinger were equally astonished. “I’ve never seen anything like that from a world-class player in my life,” said Strange.

Said Azinger: “That’s the most out of character I’ve ever seen Phil Mickelson.”

Azinger did not buy Mickelson’s explanation of the incident. “That’s good spin,” he said. Mickelson shot 81 for a 17-over 227.