Defending champion and world number one Brooks Koepka had a tricky opening to the CJ Cup in South Korea, as An Byeong-hun surged clear.
Rory McIlroy's lack of majors over the past five years means world number one Brooks Koepka does not view him as a rival.
Making his first start of the season, Brooks Koepka missed the cut at the Shriners Hospitals for Children Open.
Canadian Nick Taylor edged into the lead after the first round of the Shriners Hospitals for Children Open.
US PGA champion Brooks Koepka finished in the top five in all four majors last season, and did so with a torn patellar tendon.
The latest installment will include Brooks Koepka, Chris Paul, Christian Yelich, Liz Cambage, Kelley O’Hara and Amanda Nunes among others.
Brooks Koepka became the first player since Tiger Woods to win back-to-back PGA of America Player of the Year Awards.
Rory McIlroy joined Tiger Woods as the only golfers to win two FedEx Cup titles.
There was the ominous presence of Brooks Koepka at the top of the leaderboard of the Tour Championship after the third round.
Saturday's play was ultimately suspended due to inclement weather after lightning struck East Lake Golf Course in DeKalb County, Georgia.