England's Ross McGowan carded a sparkling 62 to set a daunting clubhouse target in the second round of the Joburg Open on Friday.
McGowan fired six birdies, two eagles and just one bogey on the West Course at Royal Johannesburg and Kensington Golf Club to finish 14 under par, three shots ahead of Chile's Felipe Aguilar.
After reaching the turn in 33, McGowan birdied the 10th and holed his second shot to the 12th for an eagle, before picking up another birdie on the 14th and holing from 12 feet for eagle on the par-five 15th to cover the back nine in 29.
The 33-year-old won the Madrid Masters in 2009, aided by a career-best 60 in the third round, but lost his card in 2011 before regaining it last November by finishing fifth in the qualifying school in Spain.
Aguilar had matched McGowan's 67 in the opening round and also went to the turn in 33 before picking up shots on the 11th, 15th and 17th to complete a flawless 65.
Welshman Stuart Manley and South Africa's Hayden Porteous were a shot further back with four and five holes remaining respectively, with first-round leader Justin Walters on nine under alongside England's Anthony Wall.