Rory McIlroy led by a stroke from Ian Poulter, Grégory Havret and Peter Hanson on ten under par as the UBS Hong Kong Open headed towards a dramatic finish at Hong Kong Golf Club.
Starting the day two behind overnight leader Alvaro Quiros, McIlroy began well with a birdie putt from 12 feet at the second, but was unable to capitalise on a number of subsequent chances.
A nice approach at the sixth was followed by a birdie putt that just slid past the hole, and the 22 year old missed another makeable one at the par three seventh.
A short birdie putt at the eighth also went begging but he finally took advantage at the ninth to move into a share of the lead on nine under par. Another birdie at the 12th then saw him move clear at the front.
Poulter, meanwhile, picked up three birdies over the front nine, the defending champion draining a mid-range putt at the ninth to climb to seven under, before picking up further shots at the 12th and 14th to move to nine under par alongside Hanson and Havret.
Hanson birdied the third from ten feet to briefly take the lead on ten under but three-putted the fourth from ten feet to drop back before bogeying the eighth. However, a birdie at the ninth saw the Swede reach the turn nine under par.
An eagle at the 12th to go with three birdies and a bogey thrust Havret into contention while Yang played the front nine in level par to also stay firmly in the hunt at eight under par.
Quiros, though, got off to a poor start with a bogey at the first after driving behind a tree, but a confident putt at the third saw the Spaniard recover his dropped shot.
However, he gave it right back at the next and then overshot the green at the par three seventh, and from a tough lie came up short with his first chip and ran 15 feet past with his second and double bogeyed.
That saw him fall to seven under before another dropped shot at the ninth left him four shots off the lead.