South Africa v Australia, 1st Test, Centurion February 11, 2014

World's best wary of Australia's looming threat

Even though they won't lose the No.1 ranking even if Australia sweep them 3-nil, South Africa still feel they have to justify their status as the best Test team going around

The first few days on top of the world feel like a dream. Over the next few it all sinks in. There is exhilaration and a massive sense of achievement.

As the weeks go by, being the best starts to feel comfortable; normal, even. Once that stretches to months, and if you keep doing whatever it is you need to do to maintain the position, it may seem like no one can ever take it away from you.

Then, somewhere along the way, uncertainty will creep in. Doubt. Nerves. That will happen the day you realise someone is coming up the mountain behind you. That day for South Africa will dawn tomorrow. Glancing down the slope, they've seen Australia looking up at them.

"They've come hunting for us and that's exciting," Graeme Smith said. "Now it's about us showing people why we are the No.1 team in the world."

This is not the first time Smith has emphasised South Africa have something to prove. Even though they won't lose the No.1 ranking even if Australia sweep them 3-nil, South Africa still feel they have to justify their status as the best Test team going around. Perhaps that thought is fueled by the fact that they have not beaten Australia in a series at home since readmission, despite winning Down Under on both their previous visits.

Smith wouldn't go as far as to say winning this series would complete his CV as captain, regarding the away wins in Australia as a "bigger highlight, considering it has been done so few times," but he hinted that the Australia visiting now is not the same as the squad that has been so successful here in the past. "They had an incredible team for a period of time," he said, adding that South Africa have that now. "It's become a big and important phase in our cricket now."

A large part of this new stage of South African cricket has focused on humility. Smith has been careful not to get too carried away with being ranked highest because he believes that is the trick to staying there.

After winning the mace in England and defending it in Australia, South Africa's brand of cricket has changed. They showed ruthlessness in the last home summer when they were victorious in all five Tests and completed all of them in less than five days. They showed resilience when they went to the UAE, where the previous top-ranked side's demise had begun, and bounced back from a hefty defeat to square the series.

Now they are back home with a different task at hand, against an opposition who have always known how to make them feel inadequate, even on their own turf. Overcoming that is the biggest challenge and that, rather than the off-field chatter, is where Smith's focus seems to lie. "When you play Australia, you expect to play a certain way and we don't expect anything different this time," he said. "All the talk, it's all a side show. It's really all about the cricket and that's what we want to focus on.

"The Aussies have been good for ticket sales and newspaper sales. It's been business as usual for us. Behind the scenes, it's been really focused. I sit here today and feel we are ready to go. We know how to win on this ground."

The series starts in Centurion, South Africa's most successful Test venue since readmission, and a place where they feel at home. The surface suits their quicks, and Smith predicted there will be something in it for them again, and if it's warm, as it often is in the summer here, it is also good for batting. They tend to draw a larger than usual and partisan crowd here and the vibe is festive.

It could be the ideal place to kick off if they are to change their home record against Australia. "It's always nice to come to familiar places where you've had success," Smith said. "You feed off past memories and things you've been able to create there."

Australia lost the only match they have played here, in 1997. That won't be too much of a bother for them because their bullishness appears to get the better of everything else. They know they cannot dethrone South Africa in this series but they can make a statement that they are on course to do it in future.

Until they do that, they seem to have admitted where the advantage lies at the moment. "South Africa are a really good team," Michael Clarke said. "They've got a great mix of youth and experience. They deserve the No. ranking, they've earned it."

For all the words uttered over the last week, as this series begins, Clarke agreed that South Africa "are the best in the world." That statement may only make South Africa want to prove it even more.

Firdose Moonda is ESPNcricinfo's South Africa correspondent