An won the 2009 U.S. Amateur Championship at Southern Hills C.C. in Tulsa, Okla., with 7-and-5 win over Ben Martin, becoming at 17 years of age the youngest winner in the championship's history. He was a semifinalist one year later in the 2010 U.S. Amateur at Chambers Bay. He broke through with his first European Tour victory in the circuit's flagship event, the BMW PGA Championship, in 2015, shooting a final-round 65 to win by six strokes over Thongchai Jaidee and Miguel Angel Jimenez. His other professional win came in the 2014 Rolex Trophy on the European Challenge Tour. An was the runner-up in the 2016 Zurich Classic of New Orleans. His father, Jae-Hyung Ahn, and mother, Jiao Zhimin, were both medalists in table tennis at the 1988 Summer Olympics in Seoul; Byeong-Hun moved to the U.S. in 2005 to attend David Leadbetter Academy in Florida, and briefly attended the University of California-Berkeley before turning pro in 2011. Got into this year's field via the top 60 in the Official World Golf Ranking as of June 11.
|2018||Shinnecock Hills Golf Club||71-76-81-78--306||+26||67|
|2016||Oakmont Country Club||74-70-73-70--287||+7||T-23|
|2010||Pebble Beach Golf Links||79-75||+12||MC|