After defeating South Africa in the 1st T20I in Cape Town, Australian all-rounder Shane Watson expects a backlash of sorts from the home side in the 2nd T20I in Johannesburg.
"It was difficult to say that the South Africans were rusty," said Watson.
"This was the start of their season whereas our group came off matches in Sri Lanka."
Watson played a vital role in Australia's victory after being dropped by former Proteas skipper Graeme Smith in the slips when he was on two.
The all-rounder made the most of the let-off by finishing with an explosive knock of 52 runs off 39 balls.
"One definitely needs a bit of luck in this game, and I had some, getting my knock going with an early chance. Having said that, though, since I came to South Africa I've felt much better about my game and I've been hitting the ball well in the nets," he added.
"You definitely need some luck to score some runs some of the time, so it's nice that it turned my way."
The Australians lost both T20 matches against Sri Lanka in Palekelle in August, and skipper Cameron White said they had been under pressure to start their six-week tour of South Africa on a winning note.
"We felt a little bit of pressure because we came off a series in which we went down in Sri Lanka," insisted White.
"I guess that's where the pressure comes from, and I suppose the start of a new series.
"The match showed that our youngsters are up for it."
Protea skipper Hashim Amla said their loss had indicated there was room for improvement at the start of a rebuilding phase under new coach Gary Kirsten.
Amla also suggested there would be some changes to their team for Sunday's clash at the Bullring.
"It's always difficult to leave some players out but I guess the selectors know what they are doing," he added.
"We'll have to see who will play on Sunday but it may be a good thing to give other players a chance to play."