AFP - Springbok fly-half Morne Steyn claimed 35 points as defending Super 14 champions Northern Bulls of South Africa triumphed 50-32 against ACT Brumbies of Australia Saturday.

Steyn scored two tries and kicked five conversions and five penalties as the Bulls reached the 50-point mark for the second successive week and regained top place on the table with a maximum 10 points from two outings.

He failed with only one kick at goal, an ambitious 60-metre penalty early in the first half at Loftus Versfeld that fell just short and the points machine emphasised his fallibility by narrowly failing with a drop goal attempt.

Scrum-half Fourie du Preez, wing Gerhard van den Heever and centre Wynand Olivier crossed the line to complete the Bulls total after a 51-34 win over fellow South Africans Central Cheetahs in Bloemfontein last weekend.

Brumbies, who launched their campaign with a nine-point Australian derby victory over Western Force in Perth, led 21-20 at half-time thanks to a try each from loose forwards Rocky Elsom and George Smith.

And they stretched that advantage to seven points 11 minutes into the second half thanks to a drop goal from new fly-half Matt Giteau and a penalty from centre Stirling Mortlock.

Steyn reduced arrears with a penalty before the 56th-minute turning point as a Brumbies line-out throw was turned over and Van den Heever, the replacement for Western Stormers signing Bryan Habana, punished the error.

Brumbies failed to clean up the ball at the tail of the line-out and Van den Heever kicked the ball ahead and gathered to cross under the posts for a try Steyn converted to give the Bulls a 30-27 lead.

It was one-way traffic from then on as the Bulls gathered strength while the Brumbies faded with the 1,500-metre-plus altitude kicking in and they did not score again until wing Pat McCabe dived over in stoppage time.

"We are going well and happy to be on top of the table. However, there is a need to be more clinical from the start," admitted Bulls skipper and Bok lock Victor Matfield.

Brumbies captain and number eight Stephen Hoiles said: "Although Loftus is one of the hardest venues to win at we have only ourselves to blame. The Bulls applied pressure in the second half and we made mistakes that were punished."

Wallaby Mortlock kicked four penalties and a conversion from seven shots at goal to contribute 14 points for the Brumbies, who face Stormers in Cape Town next Friday.