Jimenez shot a 5-under-par 67 at the Tomson Golf Club for a 14-under 274 total. Third-round leader Simon Dyson of England finished second, three shots behind, after slipping to a 4-over 76.
Next at 10-under 278 was Thailand's Prayad Marksaeng, who led at one point in the final round.
"I played really well today and played well over the week," Jimenez said. "I enjoyed myself today. I said to myself this morning I needed to be aggressive and started birdie, birdie and then made bogey on the fourth from the edge of the green."
The 40-year-old Jimenez has also won the Algarve Open and the Johnnie Walker Classic in 2004.
"I played very well from the middle of last season and I have surprised myself with three victories now," he said. "The game is very difficult to win. To win one is difficult and to win three is very nice."