HONG KONG, December 5, 2013 (AFP) - The Spanish veteran signed for a level par 70, one shot better than China's teenage prodigy Guan Tianlang but six strokes behind the early leader -- journeyman David Higgins of Ireland.
Jimenez, 49, put together a mixed round, which saw four bogeys cancel out four birdies while 15-year-old Guan collapsed to a one-over-par 71 after a blistering start which saw him hold the lead for much of the morning's play.
"There's a long way to go," a disappointed Jimenez said after taking three putts for bogey on the last hole.
"I hit it very well, apart from missing a couple of fairways. It's very difficult to put the ball close from the semi-rough because it flies.
"I had a few birdies, but it wasn't enough. I need to hole more putts and I'll be happy."
Jimenez was the pre-tournament favourite to win the $1.3 million co-sanctioned European Tour and Asian Tour event due to being the highest-ranked player at 48 in the world to be competing.
A lack of big names means the Spaniard has a great chance to break his own record, set last year, as the oldest winner on the European Tour and to match Hsieh Yung-yo of Taiwan's four wins in the southern Chinese city.
But he got his title defence off to a poor start with a bogey at the second before bouncing back immediately with birdies at the third and fourth.
Another birdie at seven on the famous Fanling course took him to two-under but he dropped a shot on the eighth to go out in one-under-par 33.
His shot of the day came on the ninth where after a pulled drive he hit a low raking hook which somehow crept onto the front of the green.
Buoyed, the winner of 19 European Tour titles then picked up a stroke on the 13th but found water at 15 before missing a short putt on the 18th to finish level par.
Earlier, Guan -- who caused a stir at the US Masters this year when he became the youngest player to make the cut in a major -- made a sensational start, completing his opening 13 holes without dropping a shot.
Along the way he picked up five birdies to lead the field at the Hong Kong Golf Club but was undone by three consecutive bogeys and a costly triple bogey on the ninth -- the penultimate hole of his first round.
"I was playing really well the first 12 holes. I made a lot of birdies and gave myself a lot of opportunities.
"After that I was really not feeling comfortable with my swing and I drove a couple in the rough," the Guangzhou schoolboy added.
"It's still all right for me and I'm looking forward to tomorrow. I'm still feeling pretty good."
Higgins' 64 leaves him one shot clear of Italy's Andrea Pavan going into Friday's second round. Seven players were tied in third on four under, including Thailand's Prom Meesawat.
"I played well tee-to-green, holed some lovely putts and had some chip-ins as well," a delighted Higgins said.
Leading scores after the first round of the $1.3 million Hong Kong Open on Thursday at the Hong Kong Golf Club, Fanling (par 70).
64 - David Higgins (IRL)
65 - Andrea Pavan (ITA)
66 - Prom Meesawat (THA), Andrew Dodt (AUS), Chih-Bing Lam (SIN), Seve Benson (ENG), Mardan Mamat (SIN), Adam Gee (ENG), Sujjan Singh (IND)
67 - Stuart Manley (WAL), Jbe Kruger (RSA), Wade Ormsby (AUS), Jaakko Makitalo (FIN), Nacho Elvira (ESP)
68 - Scott Henry (SCO), Marcus Fraser (AUS), Daisuke Kataoka (JPN), Anirban Lahiri (IND), S.S.P Chowrasia (IND), Joel Sjoholm (SWE), Espen Kofstad (NOR), Oliver Fisher (ENG), Alex Cejka (GER), Chinnarat Phadungsil (THA), Chris Doak (SCO), Alastair Forsyth (SCO)
Selected others:
70 - Miguel Angel Jimenez (ESP)
71 - Guan Tianlang (CHN)
78 - John Daly (USA)