MUNICH, June 21, 2013 (AFP) - Els added a day two 69 to his opening score of 63 to move to a 12-under par 132 total on the Munchen Eichenried course.
The 43-year old South African was struggling early after finding a water hazard at the seventh hole and walking off with a double bogey.
However the four-time Major champion then birdied four of his next seven holes and while he did drop a shot at 16, Els again stamped his class with a birdie at the last.
"I didn't feel a lot of energy today for some reason, especially on the front nine, and maybe it's jet-lag or age or something," he said.
"I made an absolute mess of two holes. I made a terrible mistake on seven trying to hit over the little creek with my drive but found the water.
"So if you take those two mistakes away, and then I had a really good round.
"I'm still in a nice position and after a nice US Open I feel as though I am swinging the club nicely."
Two players, Frenchman Alexander Levy (68) and England's Matthew Baldwin (69) share second place on 11-under par.
Germany's Martin Kaymer boosted hopes of a first victory this season despite battling an upset stomach.
Kaymer, 28, struggled to be one over par after 14 holes before he birdied two of his closing three holes in a one under par 71 and move to nine under par.
"Golf-wise, it was not the greatest day as I felt so bad on the first nine," he said.
"You could see me running back into the clubhouse after my putt at my ninth hole.
"But overall, I am playing well but just not feeling very well."
In fact, Kaymer had experienced vomiting and diarrhoea before his round while his brother was seen to deliver tablets to him during the course of his play.
And Scotland's Colin Montgomerie missed out on a planned 50th birthday celebration cake on Sunday after missing the three under par cut off mark by a shot with a pair of 71s.
Montgomerie is heading to the States on Monday where next Thursday he will make his seniors debut in the Senior Players Championship being played at the Fox Chapel Club in suburban Pittsburg.
Leading second round scores of the EPGA BMW International Open at the Munchen Eichenried Course in Munich on Friday (par 72, GBR & IRL unless stated):
132 - Ernie Els (RSA) 63 69
133 - Matthew Baldwin 64 69, Alexander Levy (FRA) 65 68
134 - Danny Willett 69 65, Bernd Wiesberger (AUT) 66 68
135 - Alexander Noren (SWE) 64 71, Miguel Angel Jimenez (ESP) 68 67, Tommy Fleetwood 66 69, Marcel Siem (GER) 67 68, Martin Kaymer (GER) 64 71
136 - Robert Jan Derksen (NED) 64 72, Peter Uihlein (USA) 70 66, Matthew Nixon 65 71, Jorge Campillo (ESP) 66 70, Peter Lawrie 67 69, Darren Fichardt (RSA) 70 66, Gary Stal (FRA) 68 68
137 - Mark Tullo (CHI) 68 69, Ross Fisher 68 69, Shiv Kapur (IND) 69 68, Joost Luiten (NED) 69 68, Brandon Stone (RSA) 66 71, Matteo Manassero (ITA) 68 69, Victor Dubuisson (FRA) 68 69, Dustin Johnson (USA) 66 71, Callum Macaulay 69 68, Thomas Bjorn (DEN) 68 69, Rafael Cabrera Bello (ESP) 67 70, Henrik Stenson (Swe) 68 69
138 - Martin Wiegele (AUT) 69 69, Oscar Floren (SWE) 68 70, James Morrison 68 70, Scott Jamieson 68 70, Seve Benson 71 67, Oliver Fisher 69 69, Tjaart Van Der Walt (RSA) 70 68, Brett Rumford (AUS) 70 68, Shane Lowry 69 69, Bernd Ritthammer (GER) 68 70, Peter Fowler (AUS) 67 71, David Higgins 67 71