The Northern Irishman, who has posted top-10 finishes in six of his last seven World Golf Championships events, only missed one fairway at Sheshan International Golf Club during a five-under-par opening round of 67.
Having started on the back nine, McDowell initially surged to seven under through 12 holes before dropping shots at the fourth and eighth.
Nevertheless, he comfortably retained top spot on the leaderboard in the second event of the European Tour's Final Series, a four-week stretch of lucrative tournaments that will conclude with the World Tour Championship in Dubai.
Six players - including former Race to Dubai winner Martin Kaymer - went round in 69 to share second position at the end of day one.
McDowell, the man they will all hope to catch, expressed satisfaction with his performance.
"I got off to a flier today but it was tough you know, the wind changed around from what [it had been like when] we played the course in practice," said the 2010 US Open champion.
"I only missed one fairway all day, which is key on this course, especially with the rough up like it is this year.
"The greens are very fast so you have to get on the right side of the flag and I managed to do that. You'll take five under every day of the week.
"I like the course, love it even, hopefully I can maintain this position going into the weekend."
Rickie Fowler and fellow Americans Brandt Snedeker and Chris Kirk were among those alongside Kaymer at three under, together with Tim Clark of South Africa and England's Tommy Fleetwood.
World number two Adam Scott began his week with a 70, as did the likes of Lee Westwood, Louis Oosthuizen, Henrik Stenson and 2012 WGC-HSBC Champions winner Ian Poulter.
Welshman Jamie Donaldson, the nearest challenger - albeit a distant one - to absent Race to Dubai leader Rory McIlroy, was one shot worse off.
Sergio Garcia - third in the world rankings and Race to Dubai - could only muster a 74, while Australia's Brody Ninyette served up a horror finish, dropping nine shots over the final three holes to come home in 49 and complete a first round of 86.