The Bulls cemented their local dominance in Super Rugby when they beat their closest rivals the Cheetahs 30-23 during the weekend's 16th round.
Super Rugby's 13th round produced another feast of high-scoring and close matches in which defence at times seemed to be an afterthought.
Three wins by Australian teams over New Zealand opponents have reshaped the Super Rugby championship during the ninth round.
The ACT Brumbies stretched their unbeaten start to Super Rugby to three matches with a 35-6 win over the New South Wales Waratahs.
South Africa and New Zealand's derby matches will determine which team holds the lead in the Super 15 when the competition goes into recess in June.
SA teams occupy three of the top six places in the Super 15 after the 12th round as the campaigns of New Zealand and Australian teams began to falter.
All Blacks captain Richie McCaw might play his first match since the Rugby World Cup after being included on the bench for Canterbury's Super 15.
Super Rugby title holders Queensland Reds head home to face the Brumbies in their first home match in a month, hoping to end their losing streak.
Chris Martin has missed out on a hat-trick, but bowled out South Africa's three best bestmen in the first Test between the Proteas and the Kiwis.
The Super 15 tournament starts this week amid fears the elongated seven-month-long season will test the patience of the rugby public.