Haotong Li shot an eight-under-par 64 to lead Frenchman Victor Perez by a single shot.

Li, 24, had seven birdies, an eagle and a bogey to card his best round at Sheshan Golf International.

Englishman Matthew Fitzpatrick and defending champion Xander Schauffele are well-placed on six-under-par.

McIlroy, who finished in a tie for third at last week's Zozo Championship in Japan, started slowly to reach the turn in level par before five birdies in six holes during the back nine catapulted him up the leaderboard.

The Northern Irishman, who has finished in the top five at this event on four previous occasions, trails Li by three alongside Corey Conners and Matthias Schwab.

Home favourite Haotong Li leads by one from Frenchman Victor Perez

Home favourite Li raced to the turn in 31 before dropping a shot on the first - his 10th - but bounced straight back with an eagle on two.

Another two birdies followed before a gutsy par save on the ninth, his final hole, kept him ahead of the rest.

Perez, who is making his World Golf Championships debut after clinching his maiden European Tour win at the Alfred Dunhill Links Championship in September, made two eagles en route to an impressive 65.

In-form Fitzpatrick, who finished runner-up in the Italian Open earlier this month, made seven birdies after opening with a bogey.

Schauffele, who defeated Tony Finau in a play-off at this event last year, birdied five of his last six holes to grab a share of third place alongside Fitzpatrick, Sung-jae Im and Adam Scott.

World number 26 Louis Oosthuizen had a hole-in-one on the par-three sixth on his way to a four-under-par 68 to sit alongside Englishman Danny Willett, Abraham Ancer and Xinjun Zhang.