|First Test, Durban, day three|
|England 303 & 172-3: Root 60*, Compton 49; Piedt 2-65|
|South Africa 214: Elgar 118*, De Villiers 49; Broad 4-25, Moeen 4-69|
|England lead by 261 runs|
Joe Root hit 60 not out as England tightened their grip on the first Test against South Africa in Durban.
The tourists are 172-3 in their second innings - a lead of 261 - and will aim to declare on Tuesday, then set about bowling the hosts out.
Earlier, Moeen Ali and Stuart Broad took four wickets apiece as South Africa's batting line-up fell apart.
Hashim Amla's men also dropped three catches on a disastrous third day for the number one ranked Test side.
The Proteas' senior fast bowler Dale Steyn was forced off with injury, star batsman AB de Villiers failed to quash rumours of his Test retirement, and the middle order surrendered meekly.
Opener Dean Elgar resisted with a superb unbeaten 118, but England remain in an excellent position to push for only a second win in 16 away Tests.
|Former England opener Geoffrey Boycott on Test Match Special|
|"England did well but South Africa, number one side in the world? Are you kidding? Whatever problems we have in our team we still look miles better than them.|
|"I don't think South Africa could have had a worse day. The batting was horrible, three catches went down, Steyn got injured and they have as much chance of winning this as I have of going to the moon. And because their batsmen are so low in confidence they only half a chance of saving the match."|
|Listen to more from Geoffrey on the TMS podcast|
"We probably have to be proactive, while still having a lot of patience with the bat," said Moeen.
"We've got a good foundation and tomorrow is about not doing what both teams have done and lose wickets in the first session in clusters.
"We're pretty calm. We're not getting overexcited."
Broad and Moeen finish the job
Broad and Moeen impressed as England brushed aside the South Africa lower order in the morning session to earn a first-innings lead of 89.
With South Africa resuming on 137-4, Broad removed Temba Bavuma with the second delivery of the day, inducing him to a drag on a wide delivery that kept low.
Then it was over to Moeen who, at the end of a year in which he has often struggled in his primary role as spinner, produced perhaps his best performance with the ball since his superb series against India in 2014.
He had JP Duminy caught at slip for two, removed Kyle Abbott for nought via a sharp bat-pad catch from James Taylor, and then enticed Steyn to sky one to Chris Woakes at mid-off.
|Elgar carries his bat|
|Elgar scored South Africa's first hundred in seven Test matches.|
|He also became the first South African to carry his bat since Gary Kirsten in 1997 and only the second since the nation's readmission to Test cricket in 1991|
After Moeen finished with figures of 4-69 - his best in an overseas Test - Steven Finn claimed the final two wickets, having Dane Piedt caught behind and getting Morne Morkel to edge to slip.
With James Anderson looking set to return from injury for the second Test in Cape Town, Finn's late burst could prove decisive in his likely battle with Chris Woakes for the third seamer's spot.
Elgar remained unbeaten following a fine innings full of discipline and application, becoming only the sixth South African to carry his bat.
Root reliable but Hales fails
Root batted with characteristic tempo and fluency to guide England to a strong position after they lost Alastair Cook and Alex Hales in an eventful afternoon session.
Skipper Cook missed a straight delivery from Piedt and was adjudged lbw for 7, while Hales battled for his 26 runs before he was caught at long-on attempting to hit the spinner over the top.
Hales is the eighth opening partner Cook has had since the retirement of Andrew Strauss, but after making only 10 in the first innings, the Nottinghamshire batsman is yet to provide evidence that England's long search for an opener is over.
That brought Root to the crease to join Nick Compton, who on his comeback appearance made his second substantial score of the match.
The South Africa-born batsman made 49 before he was caught behind off the bowling of the tireless Morne Morkel, but Root remained unbeaten, with Taylor 24 not out alongside him at the close.
South Africa in disarray
South Africa have won 10 of their past 14 series, but they looked a pale imitation of that successful side and, on this evidence, face a struggle to retain the Basil D'Oliveira Trophy.
Their batting line-up appears bedevilled by poor form, with five of their seven batsmen - Stiaan van Zyl, Amla, Faf du Plessis, Bavuma and Duminy - averaging 27 or fewer this year and without a single Test century between them in that time.
They dropped three simple catches in the field, with Elgar spilling a regulation slip chance offered by Compton on 11 and even the usually impeccable De Villiers reprieved Root on six and then dropped Compton on 45.
The sight of the clearly injured Steyn leaving the field in pain, only to return, bowl three deliveries and then trudge off again, also suggested a team in some disarray.
And then there is the ongoing uncertainty over the future of De Villiers, who before play gave an equivocal response to rumours that he could quit Test cricket, saying: "It's important to look at the schedule moving forward, that's the talk in the camp and for me maybe not to play all kinds of cricket."
|South Africa's Test results in 2015|
|2-6 January, Cape Town||Third Test v West Indies||SA won by eight wickets|
|21-25 July, Chittagong||First Test v Bangladesh||Match drawn|
|30 July-3 August, Dhaka||Second Test v Bangladesh||Match drawn|
|5-7 November, Mohali||First Test v India||India won by 108 runs|
|14-18 November, Bangalore||Second Test v India||Match drawn|
|25-27 November, Nagpur||Third Test v India||India won by 124 runs|
|3-7 December, Delhi||Fourth Test v India||India won by 337 runs|