Michel Fabrizio stayed as the man to beat as the opening day of World Superbike action drew to a close at Kyalami, the Italian leading the way throughout.
Having topped morning practice with a time of 1min 39.081secs, the Ducati Xerox rider immediately slipped beneath that within five minutes of the Q1 session starting, his effort of 1min 38.777secs holding sway up front before lowering it again by three tenths shortly afterwards.
Indeed, while the likes of Cal Crutchlow and Jonathan Rea both produced 'purple sectors' as they challenged Fabrizio, neither could sustain their pace for a whole lap, the pair falling one and two tenths short respectively in second and third.
Following a quiet morning spent getting better acquainted with the Kyalami circuit, Corser was an impressive fourth fastest on the BMW, while Leon Haslam made it five manufacturers inside the top five on the Suzuki.
Despite the varied top five, Ducati continued to look strong as five of its entries filled out top ten positions, with Carlos Checa sixth, Jakub Smrz seventh, Shane Byrne ninth and Luca Scassa tenth. Notably, however, Noriyuki Haga was the slowest of the 1198 runners down in 13th position, more than a second slower than team-mate Fabrizio.
Aprilia's Max Biaggi crept into the top ten in eighth, although he did himself no favours with a fall early on in the session.
Buoyed by his top five finish at Monza, Tom Sykes was a solid 11th on the Kawasaki, just ahead of Leon Camier, who made steady progress on the second RSV-4 as he continues to learn his way around the circuit.
Wild-card counterpart Sheridan Morais also showed an improvement between the sessions to go 16th, although the EmTek Racing rider would miss out on the final few minutes after stopping on track with a mechanical issues.
James Toseland, meanwhile, was 15th fastest, the crocked Briton contending with having not raced on the South African circuit for eight years as well this weekend.