South Africa have put themselves in a strong position at the end of the afternoon session on the second day of their first Test against Pakistan.
After a good session with the ball this morning, the hosts bowled Pakistan out for 49, but chose not to enforce the follow on.
Dale Steyn was the pick of the bowlers for South Africa, taking six wickets for just eight runs.
Alviro Petersen and Graeme Smith made a quick start to South Africa's second innings, Smith finishing the session closing in on a half-century.
The hosts lead by 277 runs heading into the evening session in Johannesburg.