FedEx Cup and US PGA Championship winner Justin Thomas made a fast start to inaugural The CJ Cup at Nine Bridges with a nine-under 63.
And the American is three shots clear of the chasing pack led by Chez Reavie, Gavin Kyle Green, Scott Brown, Marc Leishman and Patrick Reed.
“It was kind of a weird day,” Thomas told the Golf Channel.
“It started off with a really, really bad bogey and I had a seven-hole stretch there where I basically kind of went unconscious and that was pretty much most of my round.”
World number nine Jason Day is tied for 12th on four-under.
Adam Scott and Paul Casey are at level par.
There is no cut on the field for the CJ Cup