HONG KONG, 17 Oct, 2014 (AFP) - Four-time major winner Els shot a five-under-par 65 to lie on nine-under, two strokes ahead of the chasing pack at the co-sanctioned European/Asian Tour event in the southern Chinese city.
Starting on the 11th, the South African great blitzed six birdies before stumbling slightly with one bogey and then battling hard to prevent another two dropped shots at the Hong Kong Golf Club.
"I played quite nicely and a 65 was exactly what I needed to do," said Els, playing in the event for the first time.
The golf hall of famer made a flying start at the par 70, 6,699-yard course in Fanling -- picking up his six shots over the first 11 holes.
But a lapse of concentration at the short par-4 fourth led to trouble off the tee and a bogey after he tried to go for the green with his drive.
Els, nicknamed "The Big Easy" due to his tall frame and smooth swing, then made two lengthy par-saving putts on his 16th and 17th.
"I had a chance of scoring really low today and I kind of lost my momentum," he said.
"The shot was on but I didn't really have to go for it. It was a bit of a mental mistake on my part," Els added of his drive on the fourth.
"But I'm looking forward to the rest of the week and obviously I'm in a good position," he said, adding that he would celebrate his birthday but "without alcohol", after organisers presented him with a cake.
France's Raphael Jacquelin, and Australian pair Scott Hend and Cameron Smith trail Els on seven-under par.
Els finished his round just as an unfit Jimenez was starting his.
The Spanish veteran blamed food poisoning for an opening round 72 and said he was still unwell as he signed for a 70 on Friday, missing the cut in a tournament he has won four times.
"It's very disappointing," the 50-year-old said. "The problem was my physical condition. I got sick and yesterday was very, very hard.
"Today was a little better but I'm still not fit to play. It's something I couldn't do anything about."
"I came here with the intention of defending my title. It's a pity," he added.
Asia's only male major champion Y.E. Yang also failed to make the weekend, finishing on six-over par, as did Belgian Nicolas Colsaerts who crashed to a 79 after a nice 66 on Thursday.
Overnight leader Jyoti Randhawa got home in level par to lie six-under.
Leading and selected scores after the second round of the Hong Kong Open on Friday (par 70):
131 - Ernie Els (RSA) 66-65
133 - Raphael Jacquelin (FRA) 66-67, Scott Hend (AUS) 67-66, Cameron Smith (AUS) 68-65
134 - Lu Wei-chih (TPE) 66-68, S.S.P Chowrasia (IND) 69-65, Marcus Both (AUS) 67-67, Wade Ormsby (AUS) 67-67, Lee Slattery (ENG) 68-66, Marcus Fraser (AUS) 67-67, Daan Huizing (NED) 66-68, Angelo Que (PHI) 65-69, Julien Quesne (FRA) 67-67, Jyoti Randhawa (IND) 64-70, Seve Benson (ENG) 68-66
Selected scores
142 - Miguel Angel Jimenez (ESP) 72-70
146 - Y.E. Yang (KOR) 76-70
145 - Nicolas Colsaerts (BEL) 66-79
148 - Rich Beem (USA) 73-75