Australia's worst defeat in international rugby history has all but done for their coach Greg Smith. The Wallabies were humiliated 61-22 by South Africa in Pretoria, to finish last in the Tri-Nations series - convincingly won for a second time by New Zealand.

Smith, who went into the international under continuing fire following Australia's third defeat to the All Blacks this year, will have given more ammunition for those pushing for Australian Capital Territory's Rod MacQueen to be installed.

Although Smith has coached the Wallabies to wins over France, England and South Africa, it is the Bledisloe Cup clean sweep and the ignominious 39-point thrashing this weekend that have accentuated Smith's plight.

The beleaguered Wallabies coach has declined to apportion blame for the latest debacle. "We needed a change of tactics late in the game and it didn't happen," he said.

Smith is contracted by the Australian Rugby Union (ARU) until the end of Australia's tour of Argentina and Britain in October-November, but speculation is mounting that he will be axed when the ARU board meets on Monday week.

"As far as I am aware that meeting is just to review the season rather than to decide on a new coach," Smith said. Under Smith, Australia have won 12 of 19 internationals, but only two have come against southern hemisphere teams - losing all five against New Zealand and two out of four against South Africa, a sequence of defeats that has relegated the Australians to third in the unofficial world rankings behind New Zealand and South Africa.