Level with Nicolas Colsaerts on the 18th tee, he sank a 10-foot birdie putt for a six-under 65 to finish 18 under.
Shane Lowry, joint leader overnight, finished five back after a 72.
Rose’s 10th European Tour victory moved him above Masters champion Sergio Garcia into second place behind compatriot Tommy Fleetwood in the Race To Dubai standings.
Victory gave the Englishman 985,495 points in the Race to Dubai, and he is now 134,839 adrift as he attempts to finish the season as Europe’s number one for the second time, having won the Order of Merit in 2007.
And the 2013 US Open champion is only the third player – after Tiger Woods and Rory McIlroy – to follow a World Golf Championship win with another title.
Belgian Colsaerts, ranked 135th in the world and without a win since 2012, was four shots clear at the halfway stage, nine ahead of Rose.
The two men were in the penultimate group on Sunday and both had similar-length putts on the final green but after Rose holed, Colsaerts – who had birdied three holes in a row in a closing 66 – missed.
South Africa’s Dylan Frittelli finished with a 64 – the round of the day – to finish in a tie with Colsaerts.
Three-time major winner Padraig Harrington, 46, chipped in twice in his final round, including an eagle at the 15th.
He made an unlikely par at the 10th after driving into the trees and sending his second in the water before holing from 60 yards, and a four-under 67 helped him finish fourth.
Fellow Irishman Lowry found the water at the 15th and made only one birdie en route to a 72 to finish in a tie for eighth at the Regnum Carya Golf and Spa Resort.
Kiradech Aphibarnrat, second at last month’s Italian Open, missed out again as a level-par 71 meant he fell from a tie for the lead overnight to a share of sixth place.