South Africa skipper Graeme Smith has been found guilty of misconduct and was fined 10 per cent of his match fee, barely 24 hours before the Proteas take on Australia in the first Test in Johannesburg on Thursday.

"Smith was found guilty in absentia and fined 10 per cent of his match fee for failing to achieve the minimum number of overs required to be bowled in the third leg of the semi-finals of a Pro20 Series match in Durban on February 18," Cricket South Africa said in a statement on Wednesday.

Another national player Robin Peterson, who admitted guilt in writing, was also suspended from participating in two top class provincial matches for using "crude and abusive" language in a match recently.

Meanwhile, South African batsman AB De Villiers exuded confidence and said pacers Makhaya Ntini and Dale Steyn will hold the key to the first Test.

"One big difference between conditions in Australia and South Africa is that the ball swings a lot more here. Dale and the boys have the advantage and the batsmen will have to be on the ball.

"I will prefer for us to bat first, but I also wont mind at all if we see Dale, Makhaya Ntini and the other guys bowl on the first day," he said.

However, De Villiers reckoned that the Australians cannot be taken lightly as they still have enough venom in their bowling attack.

"We'll also have to know our business against their bowlers. Mitchell Johnson is a fine bowler enjoying a good season, while Peter Siddle also performed well against us.

"The Australian side is inexperienced, but is still dangerous and can beat any other side. There is still no reason why we can't beat them in our back yard," said De Villiers, who will play his 50th test tomorrow.

"My goal is to become the best batsman in the world."