Bryan Habana's late try against his old team stole a 19-14 win for the Stormers over the Bulls on Sunday morning (NZ time).
Springboks wing Habana raced clear with eight minutes to go to snatch victory as the Stormers retained first place in the South Africa conference after they had been dominated for much of the derby game away at a packed Loftus Versfeld.
A first-half try by captain Pierre Spies and the kicking of flyhalf Morne Steyn had the Bulls ahead from the 29th minute.
But Stormers flanker Siya Kolisi made a telling contribution when he broke the Bulls' defensive line and passed inside for Habana to burst clear and dive over next to the posts for the winning score.
The Stormers stay second in the overall standings. The Bulls are fifth.
Which two NZ teams look the most likely to make the Super Rugby playoffs?