They do not call Saturday "moving day" on the PGA Tour for nothing.

But Rory McIlroy took the expression to a whole new level in the third round of the Memorial Tournament at Muirfield Village.

McIlroy made the cut on the number, even par, but took all advantage of tame conditions with an early tee time on Saturday to climb 65 spots on the leaderboard by the time he posted an eight-under 64 despite finishing with five consecutive pars.

By late in his round at Jack Nicklaus' tournament, McIlroy had gone from surviving to the weekend to moving into fourth place, blowing past a who's who of contenders chasing co-leaders Kyle Stanley and Joaquin Niemann, who finished round two 11-under.

McIlroy posted the unblemished card by consistently knocking it close on greens made receptive by Friday's storms that delayed play for more than an hour.

An eagle at the fifth, along with three front-nine birdies, saw him take the turn in 31, and his back nine, though not as impressive, was bogey-free and featured consecutive birdies at 11, 12 and 13.

McIlroy may have been disappointed with just a birdie at 12 having come close to holing an ace, but he had to have been satisfied with his extremely impressive play from off the green in a performance that conjured images of his last-day charge to win the Arnold Palmer Invitational at Bay Hill in March.

The afternoon wave had yet to go out by the time McIlroy's round came to a close - Tiger Woods, who teed off some three hours after him, was at seven-under when McIlroy finished - so it is unclear if other players will go as low as the world number six. 

It is likely McIlroy will need another remarkable Sunday round to win the Memorial.