America's Peter Uihlein leads the Shenzhen International at the midway mark after shooting 68 on Friday to move a shot clear of Kiradech Aphibarnrat.
Uihlein was second after Thursday's play in China thanks to a late surge that included five birdies after the turn, including three on his last three holes.
That left him trailing overnight leader Huang Wen-yi but the 25-year-old maintained his form in the second day's play with three birdies on the outward nine.
Two more followed on the way home and even a bogey at the 470-yard 15th failed to halt his rise to the top after Aphibarnrat had enjoyed a spell at the summit.
Huang struggled to maintain his bright start - a double bogey at the 15th seeing him fall to tied 11th - while Bubba Watson also endured a difficult second round.
The world number four slipped to par overall after five dropped shots saw him card a two-over round of 74.
It means a quartet of players trail Uihlein and Aphibarnrat on tied third - Emiliano Grillo, Gregory Havret, Darren Fichardt and Matt Ford all in contention going into the final two rounds.
"It was tricky today. The wind was swirling quite a bit," Uihlein told the European Tour website.
"I got the back nine out of the way pretty quickly. I played very solid. I felt like getting anything under par on the back nine was nice and I played a pretty stress-free front nine which is always good."
Niclas Fasth secured the competition's third hole-in-one at the third while Paul Waring and An Byeong-hun were forced to withdraw due to injuries.
Nicolas Colsaerts and Peter Lawrie were among those to miss the cut.