Liang and Chapchai will be making their first appearances at the European Tour's flagship event which starts on May 24.

South Korean Yong-eun Yang, who won the 2006 Champions Tournament, Volvo Masters winner Jeev Milkha Singh of India, Thai duo Thongchai Jaidee and Thaworn Wiratchant and Singapore's first European Tour winner Mardan Mamat also boost the Asian line-up.

"I have heard a few things about Wentworth and I'm expecting windy conditions and a tough field," Liang said in a news release on Monday.

"This will be my second trip to the UK having played in Scotland (at the 2000 Alfred Dunhill Cup) but my first time to Wentworth. I have not set any expectations on myself but I hope to do my best."

Chinese number one Liang became only the second golfer from his country, after Zhang Lianwei, to win on the European Tour when he lifted the Singapore Masters title last month.

The next week Chapchai became the third player from Thailand, following Thongchai and Thaworn, to triumph on the European circuit when he recorded a wire-to-wire victory at the TCL Classic in China.

"I am excited as it will be my first visit to England," said Chapchai. "I expect the conditions to be tough but I am looking forward to it."

The PGA Championship offers a record purse of 4.35 million euros ($5.90 million), with the winner picking up 725,000 euros.