The world number 114 became the first Chinese man to hold the lead after any round at any major tournament after carding a five-under-par 65 at TPC Harding Park.

Li tops the standings heading into the round three on eight under par, ahead of a chasing pack which includes the likes of American Brooks Koepka, former world number one Jason Day of Australia and Olympic champion Justin Rose.

Koepka, seeking a third consecutive PGA Championship, remains in contention after hitting a two-under 68.

England's Tommy Fleetwood is also on six under after carding a 64, the joint-lowest round of the Championship so far.

Daniel Berger of the United States and France's Michael Lorenzo-Vera complete the players who are currently tied for second.

Li, who has missed the cut at four of the eight events he has played this year, began the day on three under par and wasted little time in moving up the leaderboard as he made five birdies over his first 10 holes.

"I didn't even think I could play like this this week, I'd got no confidence," he said.

"I said to my caddie 'no expectations'. 

"I wanted to play without stress.

"That's the key - just to play golf and try to get the win. 

"We've still got two rounds left - there is a long way to go. 

"I just want to play my best. 

"If it happens, it happens."

The tournament is taking place without spectators because of the coronavirus pandemic.

The PGA Championship is the first major of the season for the first time since 1971 after the COVID-19 crisis forced a reshuffle of the 2020 calendar.