Pakistan's top order batting crumbled against a South African pace barrage on the second day of the first Test at the Wanderers Stadium on Saturday.
Pakistan were 40 for seven at lunch, still 213 behind South Africa's first innings total of 253.
Dale Steyn sparked the collapse, taking three wickets in 14 balls at the start of the day. Jacques Kallis and Vernon Philander followed up with two wickets each as the Pakistan batsmen failed to cope with top quality bowling on a pitch with steep and sometimes variable bounce as well as some sideways movement.
Steyn struck with his fifth ball of the day after Pakistan resumed at six for no wicket, having Mohammad Hafeez caught behind for six, edging an out-swinger.
In his next over Steyn trapped new cap Nasir Jamshed leg before wicket when the left-hander went back on his stumps against a full delivery.
Jamshed, who had survived in the previous over when Philander unsuccessfully sought a review of umpire Bruce Oxenford's not out decision, was himself the victim of a failed review after being given out by umpire Billy Bowden.
Five balls later Steyn claimed the key wicket of Younis Khan, caught at first slip when he edged a perfect out-swinger.
Azhar Ali and Pakistan captain Misbah-ul-Haq survived for more than an hour before Kallis claimed two wickets in three balls, having both batsmen caught behind. Misbah was given out on review after Bowden turned down an appeal, although hot spot evidence showed only the faintest, momentary touch.
Philander, after bowling four maiden overs at the start of play, came back to dismiss Asad Shafiq and Umar Gul within three balls.
Steyn had figures of three for eight, while Philander had two for seven and Kallis two for 11.