Left-arm Australian fast bowler Mitchell Johnson seems to have established himself as the aggressor in the ongoing Test series against South Africa with his four-wicket haul on the second day of the first Test at the SuperSport/Centurion Park on Thursday.
Speaking after the draw of stumps, Johnson claimed that his performance on Thursday was better than that which set the tone for the recent Ashes series against England.
Johnson took four for 51 as South Africa crashed to 140 for six at the close, still 257 runs behind Australia's first innings of 397.
AB de Villiers was the only batsman to withstand the onslaught, scoring 52 not out.
Johnson claimed the wickets of Graeme Smith, Alviro Petersen, Faf du Plesis and Ryan Mclaren in a devastating spell of fast bowling.
He took three quick wickets, and the wicket of McLaren at a later stage in the day's play.
Sports24 quoted Johnson, as saying that he noticed that South African bowlers Morne Morkel and Ryan McLaren got extra bounce when they bowled around the wicket, and added that he wanted to see how it would work for him.
He said he believed he was a better bowler than when he played against South Africa five years ago.
South African coach Russell Domingo said that home side might just find it difficult to come out of its present predicament.
Domingo described Johnson as an "X-factor" bowler.