Matt Wallace shot a patient, two-under 70 to lead the China Open by one stroke at the halfway mark, as surprise overnight leader Jin Daxing fell off the pace on Friday.
Jin, ranked 1,426th in the world, had led courtesy of an opening 64 at Topwin Golf and Country Club in Beijing, where his countrymen Wu Ashun and Li Haotong orchestrated home wins in 2015 and 2016.
But Jin followed up his impressive start with a four-over 76 in round two to drop into a share of 22nd, five shots behind new leader Wallace.
After a birdie at the second, a bogey at four and an eagle three at the eighth, Wallace dropped another shot at 17 but made amends with a birdie on the final hole to sit clear atop the leaderboard at nine under.
American Sihwan Kim's six-under 66 saw him join Nacho Elvira (67) and Jason Scrivener (69) in a three-way tie for second.
Scrivener's fellow Australian Jason Norris posted the low round of the day, an eight-under 64 leaving him tied for ninth at six under for the tournament.
The defending champion Alexander Levy of France, who also won the event in 2014, battled to a one-over 73 to make the cut at two under.