The Crusaders' misery at Loftus Versfeld has continued, the Bulls easily winning at their stronghold despite a leaky defence which looked in trouble every time the visitors' backs got the ball.
It will be a bitterly disappointing loss for coach Todd Blackadder. The Crusaders, who last wonin Pretoria in 2008, had an edge at scrum time, and with Israel Dagg and Nemani Nadolo in good form his side cut the Bulls' up almost at will.
After a poor start the Crusaders clawed their way back and appeared set to strike only for mistakes, and referee Angus Gardner's whistle to constantly go against them.
Colin Slade was over under the posts which would have narrowed the gap to 26-23, only for Nadolo's pass to be called forward after one viewing by the TMO. The Crusaders will no doubt point to the fact that Michael Hooper's transfer for Nick Phipps' try for the Waratahs against the Blues, ruled legal, was twice as bad.
Nadolo put Crotty over the line after the final hooter, but his pass was also ruled forward. Dagg, a constant handful for the Bulls, and Nadolo, who had fewer opportunities, but who scored a typically blockbusting try, were the Crusaders' best.
Chasing the game after an intercept by replacement forward Grant Hattingh, the Crusaders lost their shape and looked disorganised and panicky. In the end it was all a bit shambolic, suggesting perhaps that their big recent victories over the Cheetahs and Lions aren't representative of a corner turned in their season.
They got off to a poor start with the Bulls dominating territory and possession and scoring early tries through Francois Hougaard and Burger Odendaal, both helped by charged down Andy Ellis clearances.
One of the few bright spots for the Crusaders was Dan Carter's goalkicking. Back in the No10 jersey, Carter kicked five from five, including the conversion for Nadolo's try from the left touchline. Stuck in mid-table, the Crusaders again have it all to do in a bid to make the playoffs. A victory would have put them in sixth. They play the Sharks in Durban next weekend.
Bulls 31 (Francois Hougaard, Burger Odendaal, Grant Hattingh tries; Handre Pollard 2 cons, 4 pens) Crusaders 19 (Nemani Nadolo try; Dan Carter con, 4 pens) Halftime: 18-16