PGA Championship winner YE Yang and Indian Masters champion SSP Chowrasia moved into the lead on the second morning of the UBS Hong Kong Open as overnight leader Udorn Duangdecha tumbled down the leaderboard.

Yang and Chowrasia improved to seven under par during their second rounds in overcast and chilly morning conditions at Hong Kong Golf Club.

Robert-Jan Derksen will begin his challenge from seven under on Friday afternoon after finishing the first day a shot adrift of unheralded Thai Duangdecha.

Duangdecha had claimed the first round lead with an eight under par 62 in the first round but carded a three over par front nine with two bogeys and a double bogey to slip back to five under overall.

The Race to Dubai leader Lee Westwood shot a four under par 66 on Thursday and gets his second round underway later in the morning with his closest challenger Rory McIlroy also still to tee off.