Reigning champions the Bulls produced a stirring second-half fightback to re-establish a five-point lead at the top of the Super 14 standings - and almost certainly clinch a place in the play-offs - after seeing off the Sharks 27-19.
The all-South African clash appeared to be going the way of the visitors, who, inspired by the accuracy of Andy Goode's kicking, established a 12-9 lead at the midway point.
But the hosts roared back and tries from Jacques-Louis Potgieter and Gerhard van den Heever handed them a lead they never relinquished despite a late score from Rory Kockott.
Goode gave the Sharks, who needed to win all of their remaining games and add a bonus point in each, an early lead with a fifth-minute penalty.
Morne Steyn missed the chance to draw the hosts level and England international Goode punished the mistake by slotting over to move the Sharks 6-0 ahead.
Steyn and Goode traded further penalties as the boot continued to dominate and when Goode converted another opportunity after 23 minutes the Sharks were full value for their advantage.
Steyn finally found his range as the half wore on and two cool penalties saw the visitors' advantage trimmed to three points at the break.
Steyn missed the chance to drag his side level at the start of the second period but it proved only temporary respite for the Sharks as the hosts upped the tempo.
Steyn made it 12-12 before the Bulls finally grabbed the opening try of the match on the hour mark.
Potgieter opened up the Sharks defence before picking out Zane Kirchner. Kirchner powered on before slipping the ball back to Potgieter to go over for a score converted by Steyn.
Steyn notched another penalty to extend the Bulls' lead to 22-12 and the game was as good as won when Fourie du Preez's kick for the corner fell loose and Van den Heever was on hand to gather and touch down.
The Sharks, having watched Steyn miss the conversion, had the final say when Kockott sprinted in from 40 metres to reduce the deficit.
Ruan Pienaar added the extras but it wasn't enough.
Scorers:
Bulls 27
Tries: Potgieter, van den Heever
Con: Steyn
Pen: Steyn 5
Sharks 19
Tries: Kockott
Con: Kockott
Pen: Goode 4
HT: 9-12