Former world number one Rory McIlroy is five shots behind leader Branden Grace following a first-round 68 at the World Golf Championship-HSBC Champions in Shanghai.
The Northern Irishman, who suffered food poisoning prior to the tournament, scored six birdies, but a double bogey on the 15th hole hampered his hopes of an early lead.
Current world number one Jordan Spieth is one shot closer than McIlroy to the lead after hitting four-under-par with six birdies, but he dropped a shot on the 13th and 17th holes.
Grace has a one-shot lead in the early stages of the tournament after carding an unblemished round of 63, scoring nine birdies in total.
Kevin Kisner, Steven Bowditch and Thorbjorn Olesen are the closest challengers one shot behind on eight-under-par, while Americans Patrick Reed and Dustin Johnson are on their tails following seven-under 65s.