The Bulls held on to beat a 14-man Waratahs team 23-17 at Loftus Versfeld which keeps them alive for another week in Super Rugby.
The Bulls outscored the Waratahs by two tries to one but the match was a tight tussle for the full 80 minutes.
Three minutes into the second half Bulls winger Bjorn Basson scored the Bulls second try of the match which equalled the record set for Bulls tries by Bryan Habana at 9 for the season.
Trailing by 20 points to 6 the Waratahs fought their way back into the match and got to within a penalty score when the turning point of the game came. Assistant referee Pro Legoete came in to report a head-butt by Pat O'Connor and was shown a Red Card.
The initial replays suggested O'Connor was clearing out a ruck and the incidedent did not appear to be an intentional head-butt however the Waratahs had already lost their man.
With this win, the defending champions have kept alive their hopes of reaching the play-off, although they are still in a situation where they will have to win their last two matches against the Sharks and Stormers respectively.
The key area where the Bulls won the match was in defence as the visiting side enjoyed the lions' share of possession throughout the contest.
Although they will be hugely disappointed in the result the Waratahs fought to the very last minute and did not back down in the physical battle they faced on the night.
After surviving close encounters with flyer Bjorn Basson who came within inches of scoring from a turnover in the opening stages, the Waratahs picked up the first points of the match courtesy of a Kurtley Beale penalty.
A good indication of just how tight the Bulls' defence was could be seen in the number of chip kicks Waratahs backline players like Berrick Barnes attempted in the opening stages of the match.
The men from Pretoria eventually managed to open their account through flyhalf Morne Steyn, but were still doing most of the tackling.
Beale converted another three-pointer to give his side a 6-3 lead and at that stage the Bulls were finding it particularly difficult to deal with Waratahs flank Chris Alcock's presence at the breakdown.
Waratahs hooker Tatafu Polota-Nau was just as busy in the contact situations where both sides competed as if their lives depended on turning over possession.
In that department Bulls fetcher Deon Stegmann was again in top shape throughout the contest.
Two telling moments late in the first half seemed to shift momentum in favour of the Bulls when the Waratahs were taking control of the match.
First scrumhalf Francois Hougaard made a telling tackle on Alcock before Steyn landed a monster hit on the Waratahs kingpin Kurtley Beale in midfield.
Steyn then nailed a penalty to draw the scores level in the 33rd minute.
The first half highlight for the Bulls came just as the visitors thought they were in the clear.
Wing Gerhard van den Heever burst though before sending centre Wynand Olivier over for a five-pointer on the half-time buzzer.
The Bulls picked-up where they left off after the break when prop Dean Greyling -- working in tandem with Stegmann -- turned the ball over inside their 22 allowing the backs some space out wide.
After coming close to scoring a try earlier Basson made up for it with his second attempt and finished the counterattack with precision.
With this try he equalled the Bulls' record of nine tries in a Super Rugby tournament held by Springbok speedster Bryan Habana.
Apart from another penalty exchange by the respective kickers, only replacement Afa Pakalani managed to trouble the scorers when he ran in the softest of tries in an otherwise brutal battle.
What should be of concern for the Bulls is that they failed to capitalise on the one man advantage they enjoyed when replacement Pat O'Connor was red carded for a headbutt in the 67th minute.
Even though the Waratahs had one less man they finished stronger but conceded a penalty in attack which allowed the Bulls to hold on to the ball for the final minute in which they wound down the clock and held on for the win.
Kurtley Beale troubled the Bulls throughout the match and was deservedly awarded man of the match.
Final Score Bulls 23 Waratahs 17
Tries - W Olivier, B Basson
Pen - M Steyn 3
Con - M Steyn 2
Tries - A. Pakalani
Pen - K Beale 4
Cards - P O'Connor (67th min) Red card.
Attendance : 23 706
Referee: Craig Joubert
Assistant referees: Pro Legoete Stefan, Breytenbach
Television match official: Shaun Veldsman
Bulls :Zane Kirchner , Gerhard van den Heever , Jaco Pretorius , Wynand Olivier , Bjorn Basson, Morne Steyn , Francois Hougaard, Pierre Spies , Danie Rossouw, Deon Stegmann, Victor Matfield (c), Bakkies Botha , Werner Kruger, Gary Botha, Dean Greyling.
Replacements: Chiliboy Ralepelle , Rossouw de Klerk, Flip van der Merwe , Dewald Potgieter, Dustin Jinka, Francois Brummer , Stephan Dippenaar.
Waratahs :15. Kurtley Beale , 14. Lachie Turner , 13. Tom Carter , 12. Berrick Barnes , 11. Sosene Anesi , 10. Daniel Halangahu , 9. Luke Burgess , 8. Ben Mowen , 7. Chris Alcock , 6. Dean Mumm [c] , 5. Kane Douglas , 4. Sitaleki Timani , 3. Al Baxter , 2. Tatafu Polota-Nau , 1. Benn Robinson
Reserves , 16. John Ulugia , 17. Paddy Ryan , 18. Pat O'Connor , 19. Dave Dennis , 20. Hugh Perrett , 21. Brendan McKibbin , 22. Atieli Pakalani