South Africa moved a giant step closer to wrapping up this year's Tri-Nations with a comprehensive 32-25 win over Australia at Perth's Subiaco Oval on Saturday. The Springboks scored four tries in a dominant display to seal their first bonus point of the season and remain unbeaten in this year's competition. They extended their lead at the top of the standings to nine points over New Zealand, who have only a slim mathematical chance of overhauling the South Africans with two games remaining for each of the three teams. The Australians replied with three late tries of their own to earn their third bonus point of the campaign but their fourth straight defeat left them out of the running for the title. The signs were ominous for the Australians from the start as the world champion Springboks raced to a 12-0 lead inside the first 10 minutes. They crossed for three tries in the opening half to establish a commanding 22-6 lead at the break then added another touchdown in the second term to build a big enough lead to snuff out Australia's late fightback. The massive Springbok pack dominated the forward exchanges to lay the foundation for their backs to pile on the points against an injury-weakened Australian side who contributed to their downfall by repeatedly surrendering possession. South Africa scrumhalf Fourie du Preez opened the scoring after five minutes when he caught the Australians napping with a simple quick tap and go. Five minutes later, outside center Jaque Fourie strolled through a gaping hole untouched after a perfectly-executed backline move off the scrum. The Wallabies opened their account with a penalty from flyhalf Matt Giteau after he had missed two earlier attempts but when wing Lachie Turner spilt a high kick, Habana swooped on the rebound to put the Springboks 22-3 in front. Giteau kicked a second penalty on the stroke of halftime then wriggled his way over to score under the posts shortly after the restart to give the Australians a brief glimmer of hope. However, the South Africans regained their composure to extend their lead to 32-13 with Habana scoring from another set move off a scrum and flyhalf Morne Steyn adding his third conversion and his second penalty. With the outcome decided, Giteau and Turner both scored late consolation tries for Australia to add some respectability to the final scoreline. The teams meet again in Brisbane next Saturday before both sides travel to New Zealand in September for their final matches against the All Blacks.