BEIJING, Oct 13, 2012 (AFP) - The home favourite was at 10 under par after rounds of 68, 67 and 68 at the OneAsia $1 million event, two strokes in front of Australian Townsend.
Korea's Yang was four shots off after he birdied the last to get into the final group.
Liang, who led by one overnight, said he would would focus on his own game, but appeared reminded of Yang's 2009 feat at the PGA Championship where he came back from a two-shot final-round deficit against Tiger Woods to win by three, becoming become Asia's first Major winner.
"The tournament is not finished yet and no-one knows what will happen, but when I play it is only me," Liang said.
Players have found scoring tough at the demanding Nanshan International Golf Club with its 6,539-metre (7,151-yard) course, but Yang remained determined to fight on.
"It's a little disappointing that I couldn't cut into the lead, but I've still got one day," he said. "Nothing is impossible. I'll try my hardest as it's definitely worth a shot. I'm not going to say it can't be done."
Between him and Liang he still needs to get past Townsend.
"I'm looking forward to the round tomorrow and playing with Liang again," the Australian said.
"He played really good, and I'm really impressed. So to play with him and Yang tomorrow will be great."
Leading scores:
203 - Liang Wenchong (CHN) 68-67-68
205 - Aaron Townsend (AUS) 69-67-69
207 - Y. E. Yang (KOR) 71-68-68
210 - Garrett Sapp (USA) 73-70-67, David McKendrick (AUS) 70-70-70, Wang Jeung-hun (KOR) 69-71-70.
211 - Mitchell Brown (AUS) 73-71-67, Terry Pilkadaris (AUS) 71-71-69, Scott Laycock (AUS) 70-71-70, Jamie Arnold (AUS) 69-70-72.