It was the second time in as many weeks they've managed to keep their opponent scoreless following their 27-0 triumph over the Hurricanes on the same ground last weekend.
It was the last North-South Derby to be staged at DHL Newlands as the hosts will move to the Cape Town Stadium next year.
The crowd of 27,301 witnessed a typical hard-fought South African derby played in perfect conditions.
The two pack of forwards worked hard on each side and the strong defence meant there were limited scoring opportunities. However, the home side landed a penalty via the boot of Springbok Damian Willemse, while hooker Scarra Ntubeni went over under a heap of bodies for his try from a lineout maul.
That handed the DHL Stormers an eight-point lead at halftime. Willemse struggled with his place kicking and he missed three more attempts at goal.
The second half continued much in the same fashion and the Cape side managed to increase their lead when wing Seabelo Senatla raced away for their second try to stretch the score to 13-0.
They tried very hard, but the Vodacom Bulls could not manage to breach the home defence, who managed to blank their opponents for a second successive week.
Scorers:
DHL Stormers (8) 13 – Tries: Scarra Ntubeni, Seabelo Senatla. Penalty: Damian Willemse.
Vodacom Bulls 0