Tries from JJ Englebrecht, Akona Ndungane, Pierre Spies and Jano Vermaak saw the Bulls triumph 35-18 over the Highlanders at Loftus.
The win was the perfect way to mark Spies reaching 100 caps in Super Rugby in front of a vocal crowd at Loftus.
The Bulls came into Saturday's clash on the back four consecutive victories, including a 34-0 whitewash over the Kings.
The tale of the Highlanders season was less successful - just one victory in their first ten matches ahead of a stern test taking on the three-time champions.
Loose ball at the ruck saw the Highlanders punished early on, Chiliboy Ralepelle recovering possession and beginning a passage of play that resulted eventually in a try for Englebrecht within the first two minutes of the match.
Colin Slade responded for the visitors with a penalty after fine work by Andrew Hore at the breakdown, before Steyn left a shot at goal hanging out to the left to keep the score at 7-3 after the opening ten minutes.
The experience of the Highlanders front-row told against their younger opponents, Jamie Mackintosh getting the better of Frik Kirsten to create three more points for Slade who cut the deficit to one.
Steyn responded with a penalty of his own to appease the earlier miss and keep the Bulls out in front.
Someway off the highest level of execution, both sides struggled with their handling and decision-making as the first half progressed.
Steyn broke the deadlock with a superb long-range penalty, his second of the night as the Bulls sought to create a healthy gap on the scoreboard. His third strike two minutes later put the them ahead 16-6.
A breakaway try for Ndungane appeared as though it should have been ruled out by the TMO due to a knock-on, yet despite conclusive footage that Jan Serfontein's pass was forward the score was still given to the dismay of the Highlanders players.
Their fortunes took a further turn for the worse after the interval, early pressure in the Bulls half cancelled out by a celebratory try for Spies down the other end that stretched the score to 30-6 after Steyn's conversion bounced in off the post.
A fourth try for the Bulls was then ruled out, Serfontein pinged for double movement diving for the line after Tino Nemani was sin-binned for a high tackle on Lionel Mapoe - a sign that the floodgates might be about to open.
Last-ditch defence from Jason Emery denied Mapoe a try of his own in the left-hand corner but the Highlanders discipline continued to let them down, prop Chris King sent to the bin to briefly reduce their numbers to 13.
Heading into the final quarter without the try bonus point, the Bulls squandered a pair of five-metre lineouts through poor execution and handling errors, although they could be afforded a level of discretion given the gulf on the scoreboard.
The better rugby came from the Highlanders, spurred on by the energy of replacements Liam Coltman, TJ Ioane and finally Japanese scrum-half Fumiaki Tanaka - the latter diving over for a consolation score with eight minutes remaining.
Still set on clinching the bonus point score, the Bulls finally delivered. A driving maul was halted on the edge of the Highlanders 22, before replacement scrum-half Vermaak burst off the base to score in the corner and seal the five-pointer.
Tamati Ellison's score after the hooter added some more respectability to the scoreline, but this was the Bulls day, extending their lead at the top of the South African Conference.
Tries: Englebrecht, Ndungane, Spies, Vermaak
Cons: Steyn 3
Pens: Steyn 3
Tries: Tanaka, Ellison
Pens: Slade 2
Yellow Cards: Nimani, King
Bulls: 15 JÃ¼rgen Visser, 14 Akona Ndungane, 13 JJ Engelbrecht, 12 Jan Serfontein, 11 Lionel Mapoe, 10 MornÃ© Steyn, 9 Francois Hougaard, 8 Pierre Spies (c), 7 Dewald Potgieter, 6 Deon Stegmann, 5 JuandrÃ© Kruger, 4 Flip van der Merwe, 3 Frik Kirsten, 2 Chiliboy Ralepelle, 1 MornÃ© Mellet.
Replacements: 16 Callie Visagie, 17 Werner Kruger, 18 Grant Hattingh, 19 Arno Botha, 20 Jano Vermaak, 21 Louis FouchÃ¨, 22 Bjorn Basson.
Highlanders: 15 Ben Smith, 14 Tino Nemani, 13 Tamati Ellison, 12 Shaun Treeby, 11 Hosea Gear, 10 Colin Slade, 9 Aaron Smith, 8 Mose Tuiali'i, 7 John Hardie, 6 Joe Wheeler, 5 Jarrad Hoeata, 4 Brad Thorn, 3 Chris King, 2 Andrew Hore (c), 1 Jamie Mackintosh.
Replacements: 16 Liam Coltman, 17 Tony Woodcock, 18 Elliot Dixon, 19 TJ Ioane, 20 Fumiaki Tanaka, 21 Hayden Parker, 22 Jason Emery.
Referee: Jaco Peyper (South Africa)
Assistant referees: Ben Crouse (South Africa), Stefan Breytenbach (South Africa)
Television match official: Shaun Veldsman (South Africa)