On a lamentable day for Australia, at least one disaster was averted.

Late on day three of the first Test at the Gabba, the outstretched arm of umpire Asad Rauf signalled Ed Cowan had been saved by a front-foot no-ball from fast bowler Morne Morkel. It also saved Australia from further damage after South Africa's fancied quicks all but wiped out the top order.

The towering Proteas paceman is a serial offender, his over-stretched front foot costing him a wicket on half a dozen occasions in his career. The South Africans launched a passionate appeal for caught behind in the penultimate over of play, and Rauf turned it down. The fielding team called for a review under decision review system, and the third umpire's first order of business is to check the bowler's front foot. Morkel's heel was on rather than behind the line, and South Africa's dismay deepened when Hot Spot showed the ball kissing Cowan's glove on its way to wicketkeeper AB de Villiers.

Thanks to Morkel's untidy footwork, Cowan survived two hours of hostile bowling from the best attack in the world to be 49 not out at stumps. The innings could yet define the opening batsman's career. His captain, Michael Clarke, was unbeaten on 34 and the pair will resume Australia's fight to stay in the first Test on day four at 3-111.

It remains a monumental task. With a full day's play lost to rain, the touring team was finally bowled out in the final session on day three for 450, before Morkel and his celebrated pace partner, Dale Steyn, tore through Australia's top order.

South African captain Graeme Smith had promised to exploit Australia's inexperience at the top. Cowan stood firm, and took on the quicks with decisive pull shots, but the Australians collapsed to 3-40 in the 10th over when Ricky Ponting was conquered for a duck.

David Warner, debutant Rob Quiney and Ponting, a veteran batsman, all succumbed within an hour, and Steyn lived up to his reputation as the best fast bowler on the planet.

He silenced the combative Warner with an angled ball that took the edge and was devoured by Jacques Kallis at second slip.

The Australians were reaching when they said Steyn did not like bowling to left-handers, but closer to the mark when they said it was hard to pinpoint weaknesses.

That point was reinforced with Steyn's acrobatics on the boundary rope at fine leg to end Quiney's maiden Test innings on nine. It was a short but fearless innings from the affable Victorian batsman, who had been a valiant contributor in the field. He had bowled 10 tight overs and taken two tough catches when he walked out in the fifth over of the innings to face Steyn.

The first ball was short and dangerous, and Quiney pulled it from in front of his nose to get off the mark. The second, he edged through the slips for his first boundary.

Then, facing Morkel, Quiney pulled again. This one was headed for six but Steyn caught it and tossed it back to himself, thinking he was about to topple over the rope.

When he completed the catch Steyn raised his finger towards the Gabba crowd to celebrate.

Ponting, coming into the Test summer with a domestic average of 188 for Tasmania this summer, lasted just five balls from Morkel.

He, too, was caught in the slips by Kallis, for a duck, the South African all-rounder's safe hands complementing his monumental innings of 147.

Kallis and Hashim Amla (104) powered the Proteas to that 450, and it looked like being a lot more before a fightback by the weary Australian bowlers. They hit a better length than on day one but looked tame compared with their South African counterparts.