England in command
Manchester, UK - Moeen Ali's dashing fifty all but put the fourth Test beyond South Africa's reach as England moved towards a series win at Old Trafford on Sunday.
When rain ended the third's play early, England was 224 for eight in its second innings - a lead of 360 runs - with Moeen unbeaten on 67.
South Africa already needed to set a new ground record if it was to end the four-match series all square at 2-2 as no side has made more in the fourth innings of a Test at Old Trafford to win than England's 294 for four against New Zealand in 2008.
Moeen made South Africa pay for Dean Elgar dropping him on 15 when a low slip chance off left-arm spinner Keshav Maharaj did not stick.
He may come in at No 8 for England but off-spinner Moeen - who earlier in this match took 20 wickets in a Test series for the first time in his career - made his name with Worcestershire as a top-order batsman.
The left-handed Moeen was especially severe on Maharaj, hitting him for three resounding sixes.
The second of those, a straight drive that saw Ali complete a 49-ball fifty - was 'caught' on the England dressing-room balcony by wicketkeeper Jonny Bairstow to the delight of the crowd.
England is bidding for a first home Test series win over South Africa since 1998, with Joe Root seeking a victory in his first Test series as England captain.
South Africa resumed on 220 for nine and was soon all out for 226 when Stuart Broad dismissed last man Duanne Olivier to give the hosts a healthy first-innings lead of 136.
South Africa fast bowler Morne Morkel then removed both Alastair Cook (10) and Tom Westley (nine) with the aid of gully catches.
At lunch, England was 53 for two, with Keaton Jennings - dropped in the slips on nought - 17 not out.
But South Africa-born Jennings was unable to cash in on his reprieve.
The Durham left-hander had added just one to his interval score when, he edged a cut off Kagiso Rabada to Hashim Amla.
Dawid Malan, who was also looking for a big score, exited soon for six but Root (49) and Ben Stokes (23), shared a stand first slip of 57 to rebuild the innings.
They both fell to paceman Olivier, only playing this match after back injuries ruled out both Vernon Philander and Chris Morris.
Olivier, who also dismissed Jonny Bairstow, ended the day with fine figures of three for 38 but that was scant consolation to his side.
England's Moeen Ali plays a shot on the third day against South Africa