The Bulls charged past the Highlanders 35-18 in Super 15 rugby on Saturday to retain control of the South African conference and move second overall as Springboks Pierre Spies and Morne Steyn reached milestones.
Skipper Spies scored one of the Bulls' four tries in his 100th Super Rugby game and Steyn became the Pretoria team's most capped player in the competition with his 117th appearance.
Center JJ Engelbrecht went in for the first try inside two minutes as the dominant Bulls capitalised on their first possession and wing Akona Ndungane's 60-meter breakout just before halftime maintained their control.
Spies scored early in the second and replacement halfback Jano Vermaak eventually secured a bonus point with the fourth try two minutes from time. Vermaak's sniping break to the left corner in the 78th minute came just as the Bulls appeared to have missed out on the extra point that moved them level with Brumbies, and above the Australian team having won one more game.
The Bulls are now 8-3 and have won five straight games in South Africa to be two points off leaders and defending champions the Chiefs.