Ntini was one of many bowlers to suffer

Then Herschelle Gibbs, who had played the seamers reasonably well, missed a straightforward Shane Warne leg-break to fall plum lbw for 34.

And when Jacques Kallis was removed cheaply by Brett Lee, the roof seemed about to cave in.

Kirsten, on one, had attempted to play no shot to a Glenn McGrath delivery but inadvertently allowed the ball to catch the edge of his bat and it looped invitingly to Warne in the slips.

The most damaging blow was the loss of Kallis - who could only glove a snorting delivery to Warne, again fielding at slip.

Gilchrist and Damien Martyn had earlier taken full toll of some ragged South African bowling.

Effortless

Martyn became the third Australian batsmen to reach three figures in the innings before Gilchrist began to batter the boundary hoardings with effortless ease and consistency.

He reached 150 shortly after Mark Boucher missed a sharp chance to stump him off the bowling of Neil McKenzie.

The Western Australian teammates put on a mammoth partnership of 327 for the sixth wicket, just 19 runs short of the best sixth wicket partnership in Test cricket by Don Bradman and Jack Fingleton in 1936-37.

Martyn and Gilchrist put on over 300 together

As the carnage continued, Gilchrist targeted the Go for Gold advertising board for which a batsman can receive 1.4m Rand for hitting, twice missing it narrowly with huge sixes.

Australia's progress was hardly checked by the departure of Martyn, who eventually slashed a wide ball from Jacques Kallis down to Gary Kirsten at deep third man.

Gilchrist reacted to the loss of his partner by taking 16 off a Nicky Boje over and Warne managed a six off the same bowler before falling the next ball after finding a leading edge to short cover.

Shortly after tea Gilchrist completed his double century which took him just 212 balls.

He hit 19 fours and eight sixes, reaching 204 not out, as Australia finally declared.