Oakmont, United States: World number one Jason Day surged into striking distance on Saturday at the US Open, leaving his rivals in golf’s ‘Big Three’ in the dust.

The Australian was languishing on five-over par after two rounds of the weather-disrupted tournament, nine shots off the pace. He produced four birdies and an eagle in a third-round 66 to reach the clubhouse on one-over 211 – six shots behind the lead held by Shane Lowry with four holes to play.

Day’s move was a stark contrast to the fortunes of world number three Rory McIlroy, who had two double-bogeys in a spectacular back-nine collapse that left him eight over and headed home early.

World number two Jordan Spieth fared better, but his attempt to gain ground in the third round yielded only an even par 70 that left him where he started on four-over.

“I was trying to push forward today,” Day said.

After four birdies in his first five holes, that push stalled with a bogey at the third – his 12th of the day.

But his four-iron into the par-five fourth gave him an eagle putt from inside 15 feet and he rolled it in.

“I didn’t know if I hit it good enough to get over the bunker,” Day said of his second shot. “I was actually quite surprised that it went behind the pin.

“It was a tough putt, but one of those ones where you pick up and you run with it because you’re not really expecting to make an eagle there.”

Although he’s six adrift, Day has two things going for him as he seeks to add the US Open title to the PGA Championship he won last year.

None of the seven players in front of him has won a major, and with his third round complete he didn’t have to return early on Sunday.

Getting into the clubhouse “really does help a lot,” said Day, who had to return early on Saturday to complete his second round then turn around and play the third.

“I had to wake up at 4:45, 5:00,” said Day, noting that Lowry and his closest chasers would have to do the same on Sunday, making the day potentially “physically and mentally a little bit tougher”.

Day was less certain that his experience of winning a major would make a difference. “I don’t think it matters in times like this when it’s just mentally and physically gruelling,” he said.

“It’s good to have a major under my belt, but I’m just trying to win the tournament.”