Cape Town - The Stormers repulsed a stirring fightback by the Bulls to retain their unbeaten record with a 20-17 win in their Super Rugby clash at Newlands on Saturday.
A penalty three minutes from the end by flyhalf Peter Grant enabled the Cape side to lead the table by two points from the Highlanders.
But the Bulls were the dominant team in the second half of a ferociously contested match, fighting back from a 14-point deficit to level at 17-17 with 13 minutes to go.
The Bulls scored two tries to one by the Stormers, but fullback Joe Pietersen landed all four penalty attempts and Grant succeeded with his only shot at goal after Pietersen went off injured.
The Bulls' Springbok flyhalf Morne Steyn converted tries by wing Bjorn Basson and centre Wynand Olivier - the latter from the left touchline - but missed two penalty attempts and was just short with a late drop goal attempt which could have put the Bulls in front.
"It was a massive effort," said Stormers captain and centre Jean de Villiers. "It shows the advantage of playing at home. There was nothing in it. I am just happy we pulled through."
Bulls skipper Pierre Spies admitted: "We were put under pressure in the first half but I am proud of the way we came back in the second half."
The visiting team looked stronger in the early stages in front of a near-capacity crowd, but Stormers went into half-time with a 14-0 lead.
Pietersen landed a penalty goal after 11 minutes and Bulls had cause to rue not taking an opportunity to equalise eight minutes later when Spies opted to go for touch instead of asking Steyn to go for posts.
A Bulls drive foundered and Pietersen added another penalty before Steyn missed from a more difficult position than the one his team had spurned earlier.
Another Pietersen penalty was followed by a try by hooker Tiaan Liebenberg after the half-time hooter.
Stormers attacked from a scrum in the Bulls 22 and after a promising double scissors move by the backs was held up, the ball went back to the forwards and Liebenberg powered over with the assistance of powerful lock Eben Etzebeth.
Bulls lock Flip van der Merwe was sin binned two minutes after half-time for taking out Etzebeth in the air at a line-out.
But his side scored 10 unanswered points while he was off the field, although Basson's try came from a counter-attack after scrumhalf Francois Hougaard picked up a loose Stormers pass and kicked ahead for Basson to chase more than half the length of the field.
The Stormers picked up four points for their victory to consolidate their lead atop the South African Conference and move back to the summit of the Overall standings. The Bulls picked up a single point for losing by seven or fewer points, and stayed second in the South African Conference and fifth in the Overall log.
In next weekend's Round 7 action, the Stormers travel to Dunedin to face the Highlanders, while the Bulls host the Crusaders in Pretoria. Teams:
15 Joe Pietersen, 14 Gio Aplon, 13 Juan de Jongh, 12 Jean de Villiers (captain), 11 Bryan Habana, 10 Peter Grant, 9 Dewaldt Duvenage, 8 Duane Vermeulen, 7 Rynhardt Elstadt, 6 Siya Kolisi, 5 Andries Bekker, 4 Eben Etzebeth, 3 Brok Harris, 2 Tiaan Liebenberg, 1 Steven Kitshoff
Substitutes: 16 Deon Fourie, 17 Frans Malherbe, 18 De Kock Steenkamp, 19 Nick Koster, 20 Louis Schreuder, 21 Burton Francis, 22 Gerhard van den HeeverBulls:
15 Zane Kirchner, 14 Akona Ndungane, 13 Johann Sadie, 12 Wynand Olivier, 11 Bjorn Basson, 10 Morne Steyn, 9 Francois Hougaard , 8 Pierre Spies (captain), 7 Jacques Potgieter, 6 CJ Stander, 5 Juandre Kruger, 4 Flip van der Merwe, 3 Werner Kruger, 2 Chiliboy Ralepelle, 1 Dean Greyling
Substitutes: 16 Bongi Mbonambi, 17 Frik Kirsten, 18 Wilhelm Steenkamp, 19 Arno Botha, 20 Jano Vermaak, 21 Louis Fouche, 22 JJ EngelbrechtStormers flyhalf Peter Grant attempts to evade Bulls No 8 Pierre Spies (Gallo Images)