Yang, from South Korea, finished the 71-hole tournament at 15-under 273 at the Suzhou Jinji Lake Golf Club for his third European Tour championship, a total that includes last year's PGA Championship. He has one other America tour tournament title.
"It is quite important for me," Yang said of the win. "There were some doubters about my game. This win won't abolish all those doubters but it will alleviate some of the pressure those doubters have put on me."
Rhys Davies, who shot 65-67 over the weekend, jumped into a second-place finish, tying Stephen Dodd, who shot 3-under 69 Sunday, for second with scores of 13-under 275. Jamies Donaldson (73), Johan Edfors (69) and Mikko Ilonen (73) tied for fourth at 276.
Yang had two birdies and one bogey in Sunday's round -- the bogey coming on the 18th hole after his drive ended up in a bunker. His second shot was long but he had enough of a lead to survive the final-hole bogey. It was his first bogey since his 5 on the par-4 third hole Friday.