Byeong Hun An took a one-stroke lead Saturday in the Waste Management Phoenix Open in front of a golf-record crowd of 204,906.
The South Korean player shot a 6-under 65 at TPC Scottsdale to reach 16-under 197. An won the 2009 U.S. Amateur at 17 to become the youngest winner in event history, and took the European Tour's 2015 BMW PGA Championship for his biggest professional victory.
Scotland's Martin Laird was second after a 65. Defending champion Hideki Matsuyama (68) was 12 under along with John Peterson (63), Canadian Graham DeLaet (65) and Michael Kim (66).
The event has drawn 596,880 for the first six days, setting records each day. With 70,000 to 90,000 expected Sunday, the tournament will shatter the overall record of 618,365 set last year.