Scott Piercy holds a one-shot lead from Brooks Koepka at the halfway mark in the CJ Cup.
Piercy surged to the top of the leaderboard with a magnificent seven-under 65 at Nine Bridges.
The wind made life difficult for some of the best players in the world on Jeju island during the first round, but conditions eased on Friday.
Piercy, eyeing his first victory since his Zurich Classic triumph six months ago, took advantage by making seven birdies in a blemish-free round.
Three-time major champion Koepka is hot on his fellow American’s heels after also signing for a 65.
Koepka started with back-to-back birdies and made another two gains before dropping a shot at the ninth to go out in 33.
The PGA Tour Player of the Year made another couple of birdies and ended his round on a high note with an eagle three at the 568-yard 18th.
Chez Reavie led by a shot after the first round but slipped down to third following a two-under 70, sitting three shots adrift of compatriot Piercy.
Alex Noren and Ian Poulter are a further stroke back, while defending champion Justin Thomas will start moving day on one under after carding a 70 – also eagling the last.
Brian Harman came up with the lowest round of the week, an eight-under 64 putting him in contention on four under.
This hole is a 568-yard par 5.
JT nearly played it in 2 shots.
— PGA TOUR (@PGATOUR) October 19, 2018