Michel Fabrizio continued to establish himself as a favourite for this weekend's World Superbike Championship races at Kyalami after claiming a dominant provisional pole position in South Africa.
The Italian was the man to beat for almost the session's entirety, his lap time of 1min 33.801secs set in the first ten minutes being only bettered some 40 minutes later by Jonathan Rea.
Nonetheless, Fabrizio responded immediately with a lap time that would prove some four tenths quicker than the Northern Irishman could muster.
Just as he was in free practice, Rea was a threat throughout the hour and would come away as Honda's leading representative this time, ahead of Ben Spies, who left it late to jump up from the lower reaches of the top ten to secure the third fastest lap of the day.
Leon Haslam and Shinya Nakano also maintained their positions in the upper echelons of the timesheets in fourth and fifth position, ahead of Noriyuki Haga on the championship leading Ducati Xerox.
Jakub Smrz made arguably the most notable improvement between the session, moving up from 16th to seventh position on the Guandalini Ducati. His new team-mate for this weekend, Gregorio Lavilla, went the other direction to come away 13th best.
Tom Sykes, Max Biaggi and Ruben Xaus rounded out the top ten, ahead of Carlos Checa and Sheridan Morais, the young South African causing a stir on home ground by going third quickest at one stage, only for a flurry of quick lap times towards the end of the session to drop him to 12th.
Further back, fellow seasonal debutants Fonsi Nieto, Shaun Whyte and Steve Martin rounded out the three latter positions in 22nd, 23rd and 24th respectively.