Steven Finn moved England to within six wickets of victory in the first Test with South Africa as the Proteas finished day four 136-4 in Durban.
Before Finn's heroics with the ball, England were inspired by a quick-fire 79 from Jonny Bairstow - the tourists' reaching 326 before being bowled out just after lunch with their lead at 415.
South Africa's response started well but a flurry of wickets either side of tea saw the hosts in trouble, Finn (3-27) the tormentor-in-chief as he dismissed Dean Elgar (40) and Hashim Amla (12) two overs apart.
The Proteas recovered from their wobble thanks to AB de Villiers (37 not out) and Faf du Plessis (9), but the latter fell fell to Finn before the close leaving them needing 280 to save the match.
England began the day keen to score quickly to allow their bowlers as much time as possible to claim the final 10 South African wickets and that led to early dismissals.
Joe Root's (73) attempts to reach three figures ended after adding 13 to his overnight total, the number four finishing 2015 with 1,385 Test runs to his name - 96 short of Michael Vaughan's 2002 record.
South Africa - who were without Dale Steyn due to his shoulder injury - had Ben Stokes (5) and James Taylor (42) back in the pavilion soon after as Dane Piedt (5-153) enjoyed his best return in Test cricket.
Bairstow's energetic innings was key for England, though, with the ball flying to all corners of Kingsmead, including three huge sixes over the leg side from the wicketkeeper-batsman.
Facing a daunting 416 to win, South Africa made a positive start as Stiaan Van Zyl and Elgar kept the early run-rate at five-an-over, the pair running well between the wickets and punishing any loose balls.
Van Zyl was the more the aggressive of the two, but he was first to fall as Stokes (1-26) found a way through his defences in the 11th over.
From 65-1 at tea, South Africa were three down 10 overs later as Finn came to the party with a fine spell of accurate fast bowling.
The prize wicket of Amla was first to fall as he inexplicably flashed at a wide delivery outside off stump, before Elgar played a questionable shot to a fuller delivery that Root gleefully hung onto at first slip.