The pair are five strokes behind Malaysia's Iain Steel and Thailand's Chinnarat Phadungsil at the Pine Valley Golf Club, the host and title sponsor of the first event sanctioned by the Asian Tour, Japan Golf Tour and the China Golf Association.

Su and Wu are joint-23rd, while compatriots Shang Lei, 26, and amateur Zhang Xinjun, 20, both shot 71 to tie for 39th.

Hu Mu, an 18-year-old amateur, and 29-year-old Li Chao are both on course to make the cut in their third successive Asian Tour event this year after shooting 72, a score matched by Liao Guiming, Liu Anda and Fan Zhipeng.

Su enjoyed the most attention, though, after bagging birdies on the first three holes and the eighth to go 4-under. However, the wheels came off his round with bogeys on nine, 11 and 12. An eagle on the par-five 13th and a bogey on the 14th summed up his topsy-turvy round.

"I shot enough birdies to score well, but had four bogeys, so it was a really up and down day," said the Vancouver-based Su, who finished third at last month's Kunming Championship and eighth in the season-opening Guangzhou Championship on the Omega China Tour.

"My irons were flying all over the place, so I had some 3-putts because I was about 20 or 30 yards from the pin.

"It was tough around holes 14 and 15, as they're par-4s but about 460 (421 m) or 470 yards playing into the wind. Then on the final three holes I had birdie putts from within 8 feet (1.8 m) but missed them all."

Wu, who played four Omega China Tour events in 2006 before spending most of last year honing his skills at the Oak Valley Golf Academy in California, is determined to make it through to the weekend after a tough start to his first season on the Asian Tour.

"I've only made the cut once in my first four events on the Asian Tour this year, so I hope this will mark my second one," said Wu, who turned pro after finishing tied-24th at December's Asian Tour Qualifying School.

"I didn't hit my irons well today but I saved pars very well and now I'm looking for a good result," Wu added.

Chinnarat birdied his last three holes on the back nine for a solid 7-under-par 65 and matched the performance of early pacesetter Steel.

Australia's Tony Carolan was a stroke back after a 66 in lone third place while South Korean youngster Bae Sang-moon, who won the SK Telecom Open last year, was in the mix in joint fourth spot alongside Chinese Taipei's Lin Keng-chi and Japanese trio of Hiroyuki Fujita, Takao Nagomi and Masao Nakajima.