The NSW Waratahs overcame the early loss of Kurtley Beale to a knee injury to beat the Bulls 31-8 and record a fourth successive Super Rugby win.
Australia back Beale, who will be joining Aviva Premiership side Wasps next season, was carried off on a stretcher cart after being injured challenging for a high ball inside the opening 30 seconds at Allianz Stadium in Sydney.
That was a blow to the home side but they still managed to come away with the win thanks to an influential display from scrum-half Nick Phipps, who scored two tries and also helped create another for Dean Mumm in between.
Angus Ta'avao then added a fourth try in the final minute for the Waratahs, with Bernard Foley converting five of his six kicks for an 11-point haul.
The Bulls responded through a Dries Swanepoel second-half try and and a first-half penalty from Tiaan Schoeman but were comfortably beaten in the end.