Although a rookie on the European Tour, the Englishman showed no signs of inexperience as he nailed seven birdies on the first round of the $3 million event.
The day's play gave him a one stroke lead over former winner Scott Strange from Australia, Dutchman Joost Luiten, South African Jbe Kruger, Gary Boyd from England, Frenchman Jean-Baptiste Gonnet and Fredrik Andersson Hed from Sweden.
Defending champion Nicolas Colsaerts from Belgium shot a 68 along with Englishman Paul Casey, while Ian Poulter, the top-ranked player in the field, shot a 71.
China's Zhang Lianwei, who won this event in 2003, and Wu Ashun lead the mainland challenge after carding 69s in an event, OneAsia, which is jointly sanctioning the event with the European Tour, said in a statement.
Reigning OneAsia Order of Merit champion Andre Stolz from Australia finished on the same score.
Calm conditions meant scoring was lower than expected on a potentially demanding layout which bears a striking resemblance to a seaside links course.
Measuring a lengthy 7,667 yards, it is the longest in Volvo China Open history -- although the tees were in a more forward position on Thursday.
Baldwin easily got the better of the course to bounce back with a vengeance after missing the cut in last week's Malaysian Open.
He triumphed on the Challenge Tour last year and finished in 10th place on the Order of Merit to secure his European Tour card.
"It was very good today so I am happy with that," said Baldwin.
"The conditions were a lot calmer today than when we played the practice round the other day."
The 26 year old turned professional in 2008 after an amateur career that saw him become a member of the England Elite squad.
The more experienced Strange lifted the Volvo China Open trophy in 2009, the year the tournament was the opening event of OneAsia's inaugural season, and went on to claim the OneAsia Order of Merit title.
"I seem to play well in China but I am not sure why I am so comfortable here," said Strange.
Like Baldwin he also carded a bogey free round.
Australian lefthander Nick Cullen, winner of OneAsia's season opening Enjoy Jakarta Indonesia Open, returned a 71, while China's number one golfer Liang Wenchong, a three-time winner on OneAsia, came in with a 73.
Leading first-round scores from the $3 million Volvo China Open in Tianjin on Thursday (par 72):
65 - Matthew Baldwin (ENG)
66 - Joost Luiten (NED), Gary Boyd (ENG), Scott Strange (AUS), Jean-Baptiste Gonnet (FRA), Fredrik Andersson Hed (SWE), Jbe Kruger (RSA)
67 - Damien McGrane (IRL), Branden Grace (RSA), Graeme Storm (ENG), Ignacio Garrido (ESP), Richie Ramsay (SCO), Marcus Fraser (AUS), Richard Finch (ENG)
68 - Pablo Larrazabal (ESP), Markus Brier (AUT), Colin Montgomerie (SCO), Robert-Jan Derksen (NED), Ricardo Gonzalez (ARG), Gareth Paddison (NZL), Alexander Noren (SWE), Nicolas Colsaerts (BEL), Paul Casey (ENG), Thorbjorn Olesen (DEN), Anthony Wall (ENG), Marcel Siem (GER), Soren Kjeldsen (DEN)
Selected:
69 - Wu Ashun (CHN), Zhang Lianwei (CHN), Andre Stolz (AUS)
71 - Ian Poulter (ENG)
72 - Nick Cullen (AUS)
73 - Liang Wenchong (CHN)
75 - Jeev Milkha Singh (IND)