"I'm hitting good, but I need some more putts. This is OK finishing on even par," said Jimenez, who was chasing his fourth Hong Kong Open title after victories in 2004, 2007 and 2012.
China's teenage sensation, Guan Tianlang, raised eyebrows when he scorched to the lead at 5 under after 11 holes.
Guan, 15, who created a stir at the U.S. Masters in April when he became the youngest player - at 14 years and five months - to make the cut at a major, rolled in five birdies as he set the Fanling fairways alight.
But the Guangzhou amateur pressed the self-destruct button on the last four holes, collecting bogey-bogey-bogey-triple bogey to finish 1-over 71.
"It is a little disappointing," Guan said. "I began well and gave myself a lot of opportunities. But towards the end I struggled with my swing and drove a couple into the rough."
Guan, playing in the company of John Daly, came close to upstaging his illustrious countrymen, China No. 1 Liang Wenchong (71) and former champion Zhang Lianwei (70).
Daly had a day to forget, struggling to an 8-over 78.
"I could drink a six-pack of beer when I was 15, but I certainly couldn't play like that," Daly said of Guan.