Rising Chinese star Chen Zihao carded a tournament-best seven-under-par 63 to move to nine-under and share the second-round lead at the Clearwater Bay Open with compatriot Yuan Tian, the 35-year-old former acrobat who sprung a 66.
First-round leader Alex Kang (69) and China's Li Jianshan (66) were two shots back at The Clearwater Bay Golf & Country Club, host and title sponsor of Hong Kong's first Ping An Bank China Tour - PGA TOUR China Series event.
England's Michael Skelton (68) was fifth at six-under, one ahead of China's Ouyang Zheng (68), American Sam Chien (67) and Australian Scott Barr (67), the reigning HKPGA Championship winner.
Charlie Saxon, second on the Order of Merit, moved to four-under with a 66, a score matched by money list leader Marty Dou Zecheng who made up ground after an opening 73.
Hong Kong No. 1 Jason Hak just made the cut after a 74. Teeing off on 10, Hak was three-under after eight holes but a triple bogey on the par-five 18th derailed his round.
Chen, 20, is looking for his first win on the PGA TOUR China Series after three runner-up finishes, including in Wuhan in May and Chongqing in September.
"This year has been my best year and I always finish okay, so I'm just looking for the win. I won a lot of junior tournaments and a couple of amateur tournaments, but I'm looking for my first pro win," said the athletic six-footer, who turned pro in late 2014.