PRETORIA, February 28, 2014 (AFP) - A round that included five birdies and an eagle, coupled with an opening 66, gave him a 131 two-round total in the co-sanctioned European Tour-Sunshine Tour event.
Fisher, whose last of four European circuit victories was the 2010 Irish Open, leads Dane Morten Madsen, another to shoot a day-two 65 at The Els Club Copperleaf.
Englishman Simon Dyson (68), joint first-round leader with South African Trevor Fisher junior, and Spaniard Carlos Del Moral (65) are on 133 and share third place.
After starting the front nine with a birdie, Fisher parred eight consecutive holes over the 7,281-metre (7,964-yard) course, the longest on the European Tour.
Birdies at 10 and 13 preceded an eagle three at 15, where the London-based golfer curled a 40-foot putt into the hole.
At 578 metres (632 yards) the par five is the second-longest hole on a layout designed by South African quadruple Major winner Ernie Els.
A brace of birdies followed, and a par on 18 gave Fisher the equal lowest round this year in the 1.5 million euro ($2.1 million) championship that debuted last season.
"It was pretty special," Fisher told reporters. "Any time you can shoot a 65 is very pleasing.
"I made a nice birdie at the start of the back nine and then hit a lovely shot into 13 to about a foot and that really got me going.
"Eagling the par-five was a huge bonus. It was a shame not to birdie the final hole, but it was nice to cosy a chip up stone dead and walk off seven under."
Madsen, calmer on Friday after flinging a ball into a green-side pool during his opening-round 67, carded two front-nine birdies and a further five on the second half.
After a flawless first 18 holes, Dyson was more erratic second time round the course with six birdies spoilt by two bogeys.
Seeking his first European triumph, Del Moral was a model of consistency with three front-nine and four second-nine birdies.
Johannesburg-born Thomas Aiken, winner of the Africa Open play-off two weeks ago, is nine strokes off the pace after shooting a one-under 71 in perfect conditions.
South African giant Dawie van der Walt won the maiden Tshwane Open, but failed to make the halfway cut in defence of the title after rounds of 78 and 74.
Leading scores after second round of European Tour-Sunshine Tour co-sanctioned Tshwane Open golf tournament at par-72, 7,281-metre (7,964-yard) The Els Club Copperleaf near Pretoria Friday (RSA unless noted):
131 - Ross Fisher (ENG) 66-65
132 - Morten Madsen (DEN) 67-65
133 - Simon Dyson (ENG) 65-68, Carlos Del Moral (ESP) 68-65
134 - Darren Fichardt 66-68, Trevor Fisher jnr 65-69, Michael Hoey (NIR) 69-65, Jake Roos 69-65
135 - Gaganjeet Bhullar (IND) 70-65, Edoardo Molinari (ITA) 70-65, Chris Wood (ENG) 67-68
136 - Jean Hugo 68-68, Hennie Otto 71-65, Danie van Tonder 66-70
137 - Jaco Ahlers 71-66, Oliver Bekker 70-67, Justing Harding 70-67, Kevin Phelan (IRL) 68-69
138 - Lucas Bjerregaard (DEN) 67-71, Merrick Bremner 69-69, Nacho Elvira (ESP) 71-67, Jared Harvey 66-72, David Howell (ENG) 69-69, Maximilian Kieffer (GER) 68-70, Mikko Korhonen (FIN) 70-68, Erik van Rooyen 66-72, Andy Sullivan (ENG) 69-69