Cape Town - Two wickets in two balls by spinner Graeme Swann put England in control at tea on the opening day of of the third Castle Test against South Africa at Newlands on Sunday.
At tea, after a session extended by 30 minutes, South Africa had 183 for five.
Paceman James Anderson struck a telling blow with his first delivery after lunch when he had Graeme Smith caught by a diving wicketkeeper Matthew Prior for 30. Smith, who was dropped by Swann on one in the second over, was looking strong and was doing much to restore South Africa's position after the early dismissal of Ashwell Prince in the first over of the day.
Jacques Kallis and AB de Villiers started bringing South Africa back into the game with a partnership of 76, their half-century partnership coming off 71 balls.
They appeared to have the measure of Swann, who was Man of the Match in the first two Tests, with Kallis in particular having no apparent difficulty.
But just as the sun came out after a wet and overcast morning, Swann struck twice in two deliveries.
De Villiers chipped the ball to Andrew Strauss at short mid-wicket, and the England captain made no mistake. De Villiers was out for 36 off 60 balls.
JP Duminy, who has had a lean time recently, got a faint edge to the next ball, and was caught behind by Prior without scoring - his second first-baller in two consecutive innings.
Boucher successfully dealt with the hat-trick ball and at tea he was not out on 37.
Meanwhile, Kallis gave a vintage performance with some sublime shots as he reached his 53rd Test half-century off 105 balls. At tea, he was not out on 55.
Their partnership was worth 56 runs at the break.
Scoreboard:
Toss: England
South Africa first innings
G Smith c Prior b Anderson 30 (90m, 49b, 3x4)
A Prince c Prior b Anderson 0 (2m, 3b)
H Amla lbw Onions 14 (74m, 56b, 2x4)
J Kallis not out 55 (161m, 116b, 6x4)
A de Villiers c Strauss b Swann 36 (84m, 60b, 4x4)
J Duminy c Prior b Swann 0 (3m, 1b)
M Boucher not out 37 (57m, 57b, 6x4)
Extras (9lb, 1nb, 1w) 11
Total (for 5 wkts) 183 - 57 overs
Fall of wickets: 1-1 (Prince 0.4), 2-46 (Amla 16.4), 3-51 (Smith 20.1), 4-127 (De Villiers 41.1), 5-127 (Duminy 41.2)
Bowling: Anderson 15-1-41-2 (1nb, 1w), Onions 13-3-35-1, Broad 14-5-39-0, Swann 14-1-55-2, Pietersen 1-0-4-0