A nervy South Africa slumped to 27/3 when bad light brought play to an early close on a rain-delayed third day, still 121 runs shy of victory in the first Test against Pakistan and a place in next June's World Test Championship.

The home side are chasing a modest target of 148 after bowling out Pakistan for 237 and if they win will be assured a place in the WTC final at Lord's.

But Pakistan kept alive their own hopes of victory as they took three wickets in the opening nine overs of South Africa's second innings with Mohammad Abbas taking two wickets and Khurram Shahzad the other as Tony de Zorzi (2), Ryan Rickleton (0) and Tristan Stubbs (1) were all trapped leg before wicket.

Aiden Markram, who top-scored for the hosts in the first innings, will resume on 22 not out, alongside skipper Temba Bavuma, when play resumes on Sunday.

South Africa had a 90-run lead over the tourists after the opening innings and although the contest ebbed and flowed through the day, will have felt they had worked their way into a winning position before they came out to bat.

Marco Jansen finished with 6/52 to put the brakes on Pakistan's hopes of a bigger second innings tally after Saud Shakeel and Babar Azam made a bright start to the day's play, which was delayed until after lunch because of a passing rainstorm. Shakeel top scored with 84.