Nicky Boje took two wickets for 25 in 20 overs and emerged as South Africa's key bowler as they chased a victory over England in the third Test at Cape Town on Wednesday.
England, who need an unlikely 501 to win, were 151 for five at the close on the fourth day. Graham Thorpe was 22 not out with Geraint Jones on two.
Left-arm spinner Boje looked the greatest threat to England's slim chances of saving the match on a wearing pitch.
England had needed to bat for just over five sessions after the home side set an improbable victory target but captain Michael Vaughan (20) and Robert Key (41) lost their wickets in the final session.
Earlier, the home side, in total control but seeking quick runs, slumped from 184-3 to 222-8 declared but that still left them ideally placed to square the five-match series at 1-1.
England were unbeaten in Tests last year, winning 11 out of 13 and their last Test defeat was against Sri Lanka in Colombo in December 2003. But the run looks set to end.
"It's going to be a hard fight, there is little doubt about it, it is just very important that the two batsmen out there play as long as possible," England coach Duncan Fletcher said. "We will not arrive here tomorrow saying the game is over."
England lost their first wicket to the second ball of the innings without a run on the board when Marcus Trescothick attempted to work a delivery from Shaun Pollock to the legside and sent a leading edge looping to Hashim Amla at silly mid-off.
KEY WICKET
Boje took the key wicket of Andrew Strauss in the eighth over before tea when he trapped him leg before wicket for 39 to end a second-wicket stand of 68 with Key.
Key was out stumped with the score on 103 and nine balls later England were 105 for four when Vaughan rashly pulled a ball from Makhaya Ntini to Jacques Rudolph at deep backward square leg.
Thorpe and Andrew Flintoff kept the South Africans at bay for 71 minutes before Pollock had Flintoff caught behind for 20.
Barring an extraordinary rearguard action on Thursday South Africa should claim victory and square the series, but Pollock said there is still work to be done.
"We have taken 15 wickets so far and we need to make a big push for another five tomorrow," he said.
"We have come a long way since the first Test but there are still wickets to get. We will be very disappointed if we didn't win from here.
"We have dismissed the top five and there is a new ball looming so things are stacked in our favour."
South Africa scored 441 in their first innings. England were skittled out for 163.
Scoreboard:
South Africa first innings 441 (J.Kallis 149, N.Boje 76, G.Smith 74; A.Flintoff 4-79)
England first innings 163 (Charl Langeveldt 5-46, Makhaya Ntini 4-50)
South Africa second innings (overnight 184-3)
G.Smith lbw b Hoggard 2
H.Gibbs c G.Jones b Flintoff 24
J.Rudolph c Key b S.Jones 23
J.Kallis run out (Giles) 66
B.Dippenaar c Vaughan b Flintoff 44
N.Boje run out (Vaughan) 4
H.Amla c G.Jones b S.Jones 10
A.de Villiers c Giles b Harmison 10
S.Pollock not out 3
M.Ntini not out 0
Extras (b-7 lb-12 nb-7 w-10) 36
Total (for eight wickets declared, 69.3 overs) 222
Fall of wickets: 1-2 2-62 3-101 4-184 5-190 6-203 7-215 8-219.
Did not bat: C.Langeveldt.
Bowling: Hoggard 10-0-46-1 (w-2), Harmison 19-3-55-1 (w-6), Flintoff 18-1-46-2 (nb-6 w-2), Giles 13-2-41-0, S.Jones 9.3-4-15-2 (nb-1).
England second innings
M.Trescothick c Amla b Pollock 0
A.Strauss lbw b Boje 39
R.Key st De Villiers b Boje 41
M.Vaughan c Rudolph b Ntini 20
G.Thorpe not out 22
A.Flintoff c De Villiers b Pollock 20
G.Jones not out 2
Extras (b-2 nb-5) 7
Total (for five wickets, 77 overs) 151
Fall of wickets: 1-0 2-68 3-103 4-105 5-146.
To bat: A.Giles, M.Hoggard, S.Jones, S.Harmison.
Bowling: Pollock 17-8-26-2 (nb-4), Ntini 15-3-30-1 (nb-1), Langeveldt 11-2-31-0, Boje 20-10-25-2, Kallis 12-4-26-0, Smith 2-0-11-0.
