The differences between South Africa and New Zealand were far greater than the ability of one attack to take 20 wickets and the struggle of the other to do half of that or that one batting line-up could score over 300 and the other just over that in both innings combined. According to Graeme Smith what really separates top sides from those in the tier below is whether they can know their game and play it.

"The biggest thing is an understanding of what needs to be done and then going and doing it," Smith said. And for that, it takes experience. South Africa, although not to the same depths as New Zealand, have been through years of what was considered underachievement when they could not reach the top ranking and hovered below.

What they learnt in those years was the ability to withstand, what they learnt after that was how to push on. "There is resilience in the squad. We've been under big pressure. We've fought back from tough positions and we've worked our backsides off to get back into games. Then, when we've had that opportunity, we've driven a bus through the door," Smith said.

At the moment, New Zealand are still on level one but only barely. Sometimes, like in the first innings, they cannot withstand. On other occasions, such as the second, they can for a little while. On every instance over the last 12 months when South Africa have been under that kind of pressure, they have survived.

The Oval, where they came back after a sorry day one; Headingley, where Kevin Pietersen's innings could have blown them away; Lord's, where Matt Prior may have derailed them; Adelaide, where Faf du Plessis rearguard action was epic; and Perth, where Hashim Amla and Dale Steyn played Australia out of the match, all stand out as examples of that. Those performances have shaped the character of the South African squad that exists now.

"There is a good degree of confidence within the squad, which enables you to play that way going forward. If guys have got good performances behind them and come off with some good wins … it's a lot easier to play that way when you haven't got that kind of confidence," Smith said.

New Zealand are side that does not have it. Hobart and Colombo aside they have not had a good last year. It's obvious even to their opposition where their faults lie. "They are struggling to find who fits in where and how can perform in certain role," Smith said. "It's more than who bats at No. 4, it's about behind the scenes and the environment. They are growing there."

South Africa have leaders other than Smith in the dressing-room, a solid top six and a bowling attack that is the envy of the cricketing world. They look a perfectly balanced unit whose only worry is to drive home their No. 1 ranking as hard as they can. "It's just about winning really, that is what you are defined by in modern-day sport," Smith said. "If you play games like this and you are dominant and you take the game forward, it's very nice."

They have been in control before but rarely as much as they were against New Zealand at Newlands, when Smith looked at the scoreboard and saw New Zealand were 26 for 9. "I couldn't quite believe we were in that situation," he said. "We bowled superbly in our new spells. We didn't start sluggish and we asked questions early on."

What was as important as the emphatic nature of the bowling for Smith was the calmness of the batting that followed. "After bowling them out for 45, the attitude we had as a batting unit was so important. It would be easy to go out there and think: 'What's happening out here?'" he said. "It was great to see Alviro push through those little sessions where he has found it tough in the past, because his potential is huge."

Petersen's hundred could end up as the least talked about but most telling act in the match. That would not matter to Smith, even if he doesn't get his due, because it's not as much about the individual as it is about the collective. "There's honesty in the group. I see us as mature team. We've grown up now." New Zealand will hope they can do the same.

Firdose Moonda is ESPNcricinfo's South Africa correspondent