Kiradech Aphibarnrat turned in 33 to lead a strong European Tour charge early on day one of the WGC-HSBC Champions.
The Thai is a three-time winner on the European Tour and produced his usual brand of entertainment at Sheshan International Golf Club with five birdies and two bogeys after starting on the tenth.
That moved him to three under alongside David Lipsky, Haydn Porteous and Matthew Southgate, with Lucas Glover and Gavin Green also at that mark.
Henrik Stenson and Mike Lorenzo-Vera were then among the group a shot off the lead.
Aphibarnrat bogeyed the 11th but made back-to-back birdies on the 13th and 14th before dropping back to level par with a bogey on the next. A hat-trick of gains from the 16th then moved him to the summit.
South African Porteous was also having a bit of a roller coaster with four birdies and a bogey in his first seven holes with American Lipsky matching the feat.
A hat-trick of birdies from the second had Southgate three under after six holes.
Green and Glover both turned in 33.
Stenson finished second here last season and the Swede holed from six feet on the tenth for birdie and picked up another shot on the 14th.
Frenchman Lorenzo-Vera bogeyed the first but bounced back with gains on the second, fourth and sixth.
Patrick Cantlay, Matthew Griffin, Bill Haas, Shugo Imahira, Chan Kim and Si Woo Kim were also two under.
There was then a large group of players two shots off the lead.
