Ashwell Prince grinds out the runs in the final session

An unbeaten stand of 111 between Ashwell Prince and Herschelle Gibbs rescued South Africa on day two of the Centurion Test against Pakistan.

Having slumped to 53-3 in reply to Pakistan's 313, South Africa ended the day on 254-4, just 59 runs behind.

Prince (77 not out) and Gibbs (58 not out) steered the home side towards parity along with Hashim Amla (71).

Mohammad Asif marked his international comeback with four wickets but received little support from his team-mates.

Seam bowler Asif, who tested positive for a banned steroid but had a 12-month ban lifted on appeal, took 4-58 and bowled with relentless accuracy.

Amla, who came to the crease in the third over of the innings, admitted: "Asif bowled excellently - he asked good questions of the batsmen and bowled in the right areas.

"The pitch is quite good for batting but it is already starting to deteriorate and help the spinners, so batting fourth could be difficult."

South Africa's hopes of a positive start were quickly dashed as Asif found the edge to send skipper Graeme Smith on his way for a duck.

He then struck again in his next over as AB de Villiers was caught by Younis Khan for four to leave them on 8-2.

Asif celebrates the fall of Amla

The same combination accounted for Jacques Kallis, who went for 18, but Amla made Pakistan pay for dropping him on four as he and Prince halted the slide by adding 77 from 25 overs before the tea interval.

Amla's third half century arrived off 89 balls with eight fours, before Asif struck again to have him caught behind by one which moved away.

Earlier in the day, Pakistan had lost their last five wickets for 57 runs.

Makhaya Ntini was the pick of the home attack with figures of 5-83.

Having resumed on 242-5, Pakistan soon lost skipper Inzamam-ul-Haq for 42 when he clipped a ball from Ntini to square leg.

Andre Nel then had Kamran Akmal caught by Shaun Pollock at mid-on for 29 after inducing a misjudged pull and Shahid Nazir (15) top-edged Ntini to Herschelle Gibbs.

Naved-ul-Hasan hit four boundaries and a six, the latter awarded after Hashim Amla failed to stay on the right side of the rope as he took a superb diving catch in the deep.

But after Danish Kaneria was caught at second slip off Ntini, Hasan was last to go for 30 when he gave a return catch to Nel.