Birdies on the third and fourth holes lifted Fisher to eight-under-par, but Luke Donald had embarked on a dazzling run of five birdies in seven holes to jump to six-under. Alexander Levy, Marcel Siem and George Coetzee were all on five-under.
Fisher was eight feet from the hole but on the fringe on the par-four third, yet managed to sink the birdie putt to get his round going.
A top-class tee shot on the 195m par-three fourth set up another birdie as he finished just four feet from the hole.
Fellow Englishman Donald was putting together a superb round as he started with a pair of birdies and then also picked up shots at the par-three fourth and the par-four sixth.
A brilliant approach shot to 10 feet on the par-five second hole set up an eagle for Siem, the German recovering quickly from a three-putt bogey at the first hole.
Coetzee rolled in a birdie putt on the first hole but found himself scrambling for pars on the next three holes.
Scotland’s Stephen Gallacher was the other golfer to get on a roll, starting his round with two birdies and then birdying three in a row from the fourth.
Jamie Donaldson will take no further part in the Nedbank Golf Challenge after withdrawing shortly before the start of the second round due to severe migraines.
The Welshman is apparently badly ill and was unable to join Mikko Ilonen and Marc Warren in the second group off the tee at 10.21am.
Donaldson shot a 74 in the first round to lie in a tie for 22nd place.