Backed-up in a record second wicket partnership by Hashim Amla, who scored a ton in the opening Test at Centurion, South Africa had no trouble building a lead of nearly 250 as they attempt to level the series at 1-1 with one to play.
The tourists, struggling to stay in the game for two days, started this morning 50 runs behind as they attempted to engineer a win that would seal a series victory.
But hopes of building a first innings lead were soon dashed when paceman Morne Morkel struck in the first over of the day to remove Graeme Swann and James Anderson in consecutive balls.
Despite the defiance of Matt Prior, who top-scored for England with 76 off 118 deliveries, the tourists were still 18 runs shy of South Africa’s total when their first innings ended.
Swann claimed the early wicket of struggling opener Ashwell Prince (15) but Smith (103 off 170) and Amla (89 off 133) guided South Africa to 224-1 midway through the final session as England wilted in the sun.

It might be difficult to appreciate on television in freezing Britain, but the 40 degree heat here is a serious factor. Ryan Sidebottom, the unselected seamer sweating in the nets (above) behind the main stand, has just told me: “This is the hottest we have ever known. Durban gets humid, but the heat here is unbelievable today.”

And former South African paceman Fanie De Villiers agreed: “It’s dangerous. Ten minutes in the sun here is like two hours in the British summer sun. I really worry about the Barmy Army out there with their shirts off. We could see plenty of them in hospital tonight. That’s how bad it is.”

Swann, forced to sweat through over after over in England's four-man attack, was second only to Australia’s Mitchell Johnson in the Test wicket-taking stakes last year with 54 victims and showed his value again here today.

The Nottinghamshire spinner made it 17 wickets in the series when he trapped Prince (15) lbw. He tried a desperate referral to third umpire Aleem Dar claiming he may have got a touch, but he was soon on his way, with England’s hot and bothered fielders offering some choice advice as he departed with the score 31 — that’s South Africa’s best opening partnership of the series so far, by four runs.
Resuming on 241-7 England lost Swann after three balls before Jimmy Anderson suffered his first ever golden duck, both falling to the superb Morkel, who ended with five for 75 off 22 overs.
But wicketkeeper Matt Prior, on 52 overnight, refused to buckle and — with Durham’s Graham ‘Bunny’ Onions at the other end — eventually fell for 76 when he edged Dale Steyn, the world’s top-ranked Test bowler, onto his stumps.
By then, he and Onions had reduced the lead from 50 to 18, and it was still anybody’s game.
Meanwhile, England have strongly denied allegations that Kevin Pietersen threw beer over a fan, who abused him.
England’s media manager Andrew Walpole said: “Neither Kevin Pietersen nor any of the other England players were involved in any kind of incident.
“There was no beer thrown from our balcony. There was absolutely no truth in the story. We are very angry and we are in contact with the ECB lawyers in London over this story. It is complete rubbish.”