Continuing his great run of form, Aussie pacer Mitchell Johnson took four-for as South Africa crashed to 140 for six at the close of play on 2nd day, still 257 runs behind Australia's first innings of 397
Centurion: Australian fast bowler Mitchell Johnson continued his Ashes series form with a devastating bowling performance on the second day of the first Test against South Africa at Centurion's SuperSport Park on Thursday.
Johnson took four for 51 as South Africa crashed to 140 for six at the close of play, still 257 runs behind Australia's first innings of 397.
Johnson took 4-51 yesterday
AB de Villiers was the only batsman to withstand the onslaught, scoring 52 not out.
The raw figures do not do justice to the destruction caused by Johnson against the world's number one rated team.
Johnson needed just four balls to strike a major blow for Australia when he dismissed South African captain Graeme Smith with a vicious bouncer. He followed up with the wickets of Alviro Petersen and Faf du Plessis in his third and fourth overs.
Peter Siddle trapped Hashim Amla leg before wicket for 17.
Smith started confidently, pulling Ryan Harris's first ball for four and taking ten runs off the first over of the innings.
Petersen scored a single off Johnson's second ball, bringing Smith on strike against the left-arm fast bowler, who destroyed England by taking 37 wickets at an average of 13.97 during the Ashes series.
Johnson's first ball to Smith was short and there was a half-hearted appeal as it thudded off Smith's thigh pad to short leg.
The next ball was a fast bouncer which climbed towards Smith's head. The batsman lifted his bat in front of his face and the ball looped over the slips, with Shaun Marsh running back from third slip to take a fine catch.
Petersen made only two before flashing at Johnson to be caught by wicketkeeper Brad Haddin and Du Plessis followed soon afterwards, fending another short delivery to Michael Clarke at second slip.
Hashim Amla was leg before wicket to Peter Siddle to reduce South Africa to 43 for four before AB de Villiers and JP Duminy staged a minor recovery with a fifth wicket stand of 67.
Johnson was involved in Duminy's dismissal taking a superb diving catch running back from mid-off when Duminy mistimed a lofted drive against off-spinner Nathan Lyon.
Johnson the bowler struck again when he bowled Ryan McLaren, beating the all-rounder for pace.
Australia earlier lost their last six wickets for 66 runs.
Marsh and Steve Smith took their fifth wicket stand to 233, seeing off the threat of Dale Steyn and Vernon Philander with the second new ball, before Smith was out for 100, caught at second slip off Ryan McLaren.
Smith took 33 balls to advance from his overnight 91 to his fourth Test century, made off 211 deliveries, but was out two balls later.
Brad Haddin, one of the stars of Australia's 5-0 series win over England, lasted just three balls before he swung across the line against left-arm spinner Robin Peterson and was leg before wicket without scoring.
Marsh took his overnight score of 122 to a Test-best 148 before Philander came back into the attack and had him caught at first slip.
Dale Steyn and Robin Peterson wrapped up the innings soon after lunch, with Steyn bowling Ryan Harris and Peter Siddle to finish with four for 78, while Peterson bowled Johnson for a hard-hit 33.
Brief scores: Australia 397 (S Marsh 148, S Smith 100; D Steyn 4-78) lead South Africa 140-6 (AB de Villiers 53 batting; M Johnson 4-52) by 257 runs