The Chandigarh golfer sank four birdies and three bogeys in his final round to finish with a four-day total of 20-under 286 at the Colin Montgomerie-designed Royal Golf Club course here on Sunday.
Paul Casey sank a clutch six-foot putt en route to a brilliant four-under 68 in the final round to end his 20-month barren run, clinching the Volvo Golf Champions title. He became richer by 283,329.
Casey, who was third on the Official World Golf Ranking before he tore a rib muscle practising for the 2009 Open Championship, will move back into the top six and will be fifth if Phil Mickelson finishes worse than second on US Tour this week in San Diego.
That would also mean an incredible four Europeans in the top five - Lee Westwood, Martin Kaymer and Graeme McDowell remaining first, second and fourth.
Casey came to the 429 yard last level with Swede Peter Hanson.
Hanson went from rough to sand and then missed from ten feet and with a bogey five dropped into a tie for second with Miguel Angel Jim'z.
Northern Ireland's Darren Clarke, another Swede Johan Edfors and South African James Kingston all slipped up after holding at least a share of the lead.
Clarke had bogey sixes on both the ninth and 13th and finishing with a double bogey.
Jimenez's chances were alive again when he birdied the last and Hanson bogeyed it, but Casey kept his nerve and got up and down from the rough by the green to squeeze home.
It was Casey's 11th European Tour win and his third European Tour victory in one of the Desert events, following the 2007 and 2009 Abu Dhabi Golf Championship.