PRETORIA, March 1, 2014 (AFP) - The 33-year-old English golfer, whose last title was the 2010 Irish Open, fired a 67 at The Els Club Copperleaf west of Highveld city Pretoria.
His see-saw front nine produced five birdies and two bogeys and he claimed another two birdies on the back nine of the 7,281-metre (7,964-yard) layout.
Fisher, a stroke ahead at the halfway stage of the 1.5 million euro ($2.1 million) event, carded a five-under-par 67 for a 198 total after 54 holes.
Ranked 82 in the world, Fisher is aiming for a top-50 place soon and has no intention of playing safe on Sunday in the final round.
"I feel like I belong in the top 50 -- I have been there before but struggled during the past few seasons to return," said the four-time European Tour winner.
"I'm certainly not going out tomorrow (Sunday) to hit fairways and greens and make pars. I want to force the other guys to shoot a silly-low score to beat me.
"I feel like I am playing as good as I ever have -- similar to 2010 when I was contending for Majors and got myself into the Ryder Cup team."
Michael Hoey from Northern Ireland, who climbed into contention Friday with seven consecutive back-nine birdies, lies second after a mixed third trek over the longest European Tour course.
Like Fisher, Hoey delivered a mix of birdies (six) and bogeys (three) in the second edition of the Tshwane Open, which South African Dawie van der Walt won last year.
Englishman Simon Dyson, who shared the opening-round lead, and Spaniard Carlos Del Moral lie third on 204, six shots adrift of Fisher.
Dyson could manage only a one-under 71 composed of three birdies, two bogeys and 13 pars over a course designed by South African quadruple Major champion Ernie Els.
Del Moral, seeking his maiden European victory, also had a three birdie-two bogey round of 71 on a day when wet weather replaced a sunny opening half of the tournament.
A group of seven golfers on 205 -- seven shots behind Fisher -- includes Italian Edoardo Molinari (70) and Irishman Kevin Phelan (68).
Englishman Robert Rock is a shot further back after the best third round -- a 65 that included 10 birdies and a triple-bogey six at the penultimate hole.
Leading scores after third 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 Saturday (RSA unless noted):
198 - Ross Fisher (ENG) 66-65-67
203 - Michael Hoey (NIR) 69-65-69
204 - Simon Dyson (ENG) 65-68-71, Carlos Del Moral (ESP) 68-65-71
205 - Merrick Bremner 69-69-67, Darren Fichardt 66-68-71, Trevor Fisher jnr 65-69-71, Edoardo Molinari (ITA) 70-65-70, Hennie Otto 71-65-69, Kevin Phelan (IRL) 68-69-68, Danie van Tonder 66-70-69
206 - Oliver Bekker 70-67-69, Robert Rock (ENG) 70-71-65, Jake Roos 69-65-72