Hideki Matsuyama could do no wrong after taking the tournament lead on Friday, while Tiger Woods struggled again.
Patrick Reed continued his consistent showing at the Northern Trust to grab the lead after the third round.
Dustin Johnson backed up his opening-round 63 to take the lead at the Northern Trust.
South Korea's An carded a four-under-par 66 to preserve his position atop the leaderboard following Saturday's third round in Greensboro.
An Byeong-hun carded a five-under 65 to grab the outright lead at the Wyndham Championship.
South Korean duo An Byeong-hun and Im Sung-jae share a one-stroke lead at the Wyndham Championship.
World number one Brooks Koepka celebrated a three-stroke victory after carding a five-under-par 65 in Memphis on Sunday.
Jon Rahm produced an impressive eight-under 62 to lead the WGC-FedEx St. Jude Invitational.
Brooks Koepka could not land another major at The Open but his stunning season has earned him another place in golf's history books.
After playing himself in contention at The Open, Jordan Spieth spoke of why he feels he has such a good record on links courses.