McIlroy, bidding for back-to-back major wins, needed to climb the leaderboard on ‘moving day’, starting it tied for 30th after a second-round 67 helped him fight back from a four-over opening round of 74.

He started the day one over par, just five back from co-leaders Alex Smalley and Maverick McNealy, and teed off alongside five-time major winner Brooks Koepka in glorious conditions at Aronimink Golf Club.

McIlroy reached the turn at three under for his round, while Rose was also two back with three to play and American Chris Kirk was a shot off the lead as he neared the end of his round after racking up seven birdies.

Only two players had shot lower than three under across the first two days but the course appeared more accessible as Saturday got under way.

The wind which had added to the challenge on the greens over the first two days gave way to warm, calm conditions as the early starters racked up the birdies.

McIlroy was well supported by the spectators in south-west Philadelphia and, with 11 major championships between them, he and Koepka drew an enormous following.

The Northern Irishman started his pursuit of a low score in ideal fashion, with a superb approach on the first yielding an opening birdie.

He missed a great birdie chance on the second before a three-putt bogey at the fourth checked his progress.

McIlroy hit back though with birdie at the fifth before adding another at the sixth thanks to a booming drive onto the green of the 390-yard hole, as he moved to one under.

He made his fourth birdie at the par-five ninth to turn in 32.

Rose only made the cut courtesy of a stunning chip-in eagle at the last on Friday and he made the most of his reprieve.

The 45-year-old, who admitted yielding the midway lead of the Masters last month was a “tough loss” to overcome, racked up five birdies to shoot 30 on the front nine.

The Englishman, who won the AT&T National at this course in 2010, moved to within a shot of the lead with another birdie at 13 before a first bogey of the round at 14 halted his momentum.

With low scores clearly on offer, McIlroy, Rose and the other morning starters will have to hope the leaders remain within reach heading into Sunday’s final round.

World number one Scottie Scheffler was two back from the overnight lead and starts his round at 1.40pm local time (6.40pm BST).

The early charge had come from American Michael Kim. He birdied six of the first seven holes to close within two of the lead but his extraordinary round turned into a roller coaster on the back nine – with three bogeys, a double bogey, an eagle and a birdie as he carded 67.