Los Angeles - South Korea's An Byeong-Hun fired six birdies in his six-under par 65 on Saturday to take a one-shot lead over Scotland's Martin Laird at the USPGA Tour Phoenix Open.
An, the overnight co-leader, is seeking his first USPGA Tour title, although the 25-year-old has notched a win on the European Tour, at the 2015 BMW PGA Championship, and has won as a professional on the Challenge and Korean tours.
"My goal is to play bogey free and play smart," said An, whose 16-under par total of 197 put him one stroke in front of Laird -- who snaked in an 11-foot birdie putt at TPC Scottsdale's 18th to cap his own 65 for 198.
Laird had rebounded from a bogey at the second with four birdies in a row starting at the third, and picked up three more strokes coming in.
Defending champion Hideki Matsuyama remained within striking distance, carding his second straight 68 to head a group sharing third on 201.
Japan's world number five balanced three bogeys with six birdies, including a thriller at the par-three 16th where his tee shot settled less than two feet from the pin.
It drew roars of approval from the massive gallery at 16, where stadium-style seating makes for an atmosphere more like that of a football match than a golf tournament.
The course is designed for huge crowds and it was another record-setting day in that department. Saturday's attendance was estimated at 204,906, breaking the record of 201,003 set on Saturday last year, which was the first time any tournament had surpassed 200,000 for a day.
"It's crazy...insane," An said of the crowds. "It's pretty cool. I'd never seen people like this. I think it's fun, as long as nobody yells at my downswing."
Matsuyama was joined on 12-under by John Peterson, who carded a storming 63 to power up the leaderboard, along with Canada's Graham DeLaet (65) and American Michael Kim (66).
Peterson strung together four birdies in a row starting at the second before his momentum was slowed by a double-bogey at the par-four sixth.
He got back on track with a birdie at the ninth, and nabbed three birdies and an eagle at the par-five 13th coming in.
Five-time major winner Phil Mickelson, a fan favorite who attended Arizona State University and has won the Phoenix Open three times, carded a 65 that left him six adrift.
"I'm excited about tomorrow's round," Mickelson said. "If I can get off to a good start and shoot 3-, 4-, 5-under on the front nine, that back nine has so much excitement and opportunity that I would love to play those final six holes with a chance, because there are a lot of birdies and eagles out there."
Leading third-round scores on Saturday from the USPGA Tour Phoenix Open at par-71 TPC Scottsdale in Arizona (USA unless noted):
197 - An Byeong-Hun (KOR) 66-66-65
198 - Martin Laird (SCO) 67-66-65
201 - John Peterson 66-72-63, Graham DeLaet (CAN) 67-69-65, Michael Kim 69-66-66, Hideki Matsuyama (JPN) 65-68-68
202 - Mark Leishman (AUS) 68-69-65, William McGirt 69-67-66, J.J. Spaun 71-64-67, Matt Kuchar 64-69-69, Brendan Steele 65-67-70
203 - Phil Mickelson 68-70-65, Webb Simpson 67-71-65, Shane Lowry (IRL) 69-68-66, Daniel Berger 71-66-66, Louis Oosthuizen (RSA) 68-67-68
204 - Jon Rahm (ESP) 70-69-65, Camilo Villegas (COL) 71-68-65, Scott Brown 66-70-68, Rickie Fowler 67-68, 69
205 - Jordan Spieth 70-68-67, Lucas Glover 68-72-65, Troy Merritt 74-66-65, Robert Garrigus 66-70-69
206 - Boo Weekley 70-68-68, Kevin Na 68-70-68, Grayson Murray 72-67-67, Brian Stuard 71-67-68, Russell Henley 71-69-66, Morgan Hoffmann 69-67-70, Jason Bohn 72-68-66, Zach Johnson 70-66-70, Brian Harman 69-67-70, Billy Horschel 70-71-65