Aaron Rai saw his halfway lead cut in half early on day three of the Honma Hong Kong Open presented by Amundi.
The Englishman began the day four strokes clear of closest challenger Hyowon Park after treating local crowds to a course-record 61 on Friday.
But South Korean Park had closed the gap to two shots after six holes on Saturday, with birdies at the second, third and sixth moving him to 13 under par.
Rai, meanwhile, carded just one birdie in his first six holes, rolling in from five feet at the fourth to get to 15 under.
Matthew Fitzpatrick was two shots behind Park in third after firing an eagle and a birdie in his first seven holes on day three.
