An Byeong-hun and Brendan Steele are a stroke clear atop the leaderboard after the second round of the Phoenix Open.
Respective rounds of 66 and 67 ensured An and Steele earned the lead at the halfway mark of the PGA Tour tournament on Friday.
South Korean An and a flawless Steele, who did not drop a shot, teed off early in the day to set the pace and sit 10 under through 36 holes at TPC Scottsdale.
Defending champion Hideki Matsuyama is in contention following his three-under-par 68.
Matsuyama grabbed a share of the lead with one hole to play, but he bogeyed the 18th to drop back to nine under.
Overnight leader Matt Kuchar is alongside Matsuyama following his second-round 69, while Martin Laird (66) and Kang Sung (65) are also a shot off the pace.
Rickie Fowler, who lost in a thrilling play-off last year, is two strokes further back.
Fowler shot a three-under-par 68 to get to seven under, and he is joined by Michael Kim (66) and Louis Oosthuizen (67).
Former world number one Jordan Spieth, meanwhile, is six shots behind the leading pair.
-- PGA TOUR (@PGATOUR) February 3, 2017
Spieth did rise nine positions with a 68, which included six birdies, though he double-bogeyed the 18th following a flawless front nine.