Mitchell Johnson vows to improve further against World No.1 South Africa

Australian fast bowler Mitchell Johnson produced career-best match figures as he sent South Africa crashing to a humiliating 281-run defeat on the fourth day of the first Test at SuperSport Park on Saturday - then said he is looking to improve.

Johnson followed up his seven for 68 in the first innings with five for 59 as South Africa were bundled out for 200. As he did in the first innings, Johnson took a wicket in his first over and dismissed both South African opening batsmen cheaply to set the hosts on a slide from which they were unable to recover.

"I said to (captain) Michael (Clarke) after the first innings that there was definitely room for improvement," said man of the match Johnson.

"You are always trying to improve as a player, trying to get better, and that's what I'll still be trying to do throughout this series. Playing away from home, that's where you test yourself as a player. We're up against the number one side so that's good motivation for us to keep getting better."

Clarke said Australia's performance over the four days matched the cricket they played in beating England 5-0 in the recent Ashes series.

"Our batters deserve a lot of credit for the runs they got on quite a nasty wicket and our execution with the ball was a lot better in the second innings," he said. "Two things we have spoken about is attitude and hunger. I think our attitude at the moment is outstanding. We're finding ways to get back into the game and ways to run with momentum when we have it."

But Clarke said the Australians expected South Africa to fight back.

"A lot of work to do"

"We're playing the number one team in the world and the only way to beat them is to be at your best all day, every day. We started well but we know we've got a lot of work to do," he said.

It was a match dominated almost entirely by Australia, who thoroughly outplayed the team currently ranked number one in Test cricket. "We were outplayed from the word go," said South African captain Graeme Smith. "It was one of the most disappointing four days we have had in my time."

Smith said South Africa had a good opportunity to take control when they had Australia 98 for four after sending them in. But he admitted that he had made the wrong decision at the toss, condemning his team to batting as conditions deteriorated on a dry, cracked surface.

"I have never seen this wicket play like this before," he said.

Johnson's match figures of 12 for 127 bettered his previous match best of 11 for 159 against South Africa in Perth in 2008/09. AB de Villiers, who made 91 in the first innings, again provided the only significant resistance to the Johnson-inspired bowling attack, hitting 48 before driving Johnson to short cover where Steve Smith held a stinging catch.

Given the performance of Johnson in particular, it will be difficult for South Africa to come back in the two remaining Test matches. South Africa have not been beaten in a series since Australia beat them, also in South Africa, in 2008/09.