No player broke par in a final round hit by a powerful rain storm. McGrane, who entered the final round with a three-stroke lead, finished at 10-under 278. Simon Griffiths (74) and Oliver Wilson (79) of England and Michael Lorenzo-Sera (79) of France were tied for second at the Beijing CBD International course.
McGrane dropped two shots on the opening eight holes but then made two birdies in three holes.
It was the first title for 37-year-old McGrane since he joined the European Tour in 2003, claiming the winners prize of $366,287 in the event jointly sanctioned by European and Asian Tour.
I have been thinking about winning one tournament for so long and this week everything went my way, McGrane said. I had good fortune, loved the course, and the bad weather didnt put me off my game today.
Defending champion Markus Brier of Austria shot 76 to finish 10 strokes back, along with the tournaments two highest-ranked players'Graeme McDowell (75) of Northern Ireland and Mark Brown (77) of New Zealand.
Brown had a triple-bogey on the final hole.