An won the 2009 U.S. Amateur Championship at Southern Hills C.C. in Tulsa, Okla., with a 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 at Chambers Bay. He broke through for 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. An also was the runner-up in the 2016 Zurich Classic of New Orleans on the PGA Tour. 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 the David Leadbetter Academy in Florida, and briefly attended the University of California-Berkeley before turning pro in 2011.
|2020||Winged Foot Golf Club (West Course)||71-76||+7||MC|
|2019||Pebble Beach Golf Links||70-72-68-71--281||-3||T-16|
|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|