Morkel takes five as Zimbabwe crumble to 68 all out
The inaugural four-day Test could be over inside two days after South Africa skittled Zimbabwe for only 68 at St George's Park on Wednesday.
Zimbabwe resumed on 30-4 in reply to 309-9 declared on day two and were unable to dig themselves out of a hole, Morne Morkel taking 5-21 after claiming three wickets under the lights on Tuesday.
The International Cricket Council gave the go-ahead for the match in Port Elizabeth to be trialled over four days rather than five, but it is unlikely to last even the shortened distance.
Kyle Jarvis (23) and Ryan Burl (16) were the only batsmen to reach double figures as the tourists were dismissed for their fifth-lowest Test total, South Africa needing only 14 overs of the opening session to wrap up the innings.
Stand-in captain AB de Villiers, again donning the wicketkeeping gloves in the absence of hamstring-injury victim Quinton de Kock, took four catches in Zimbabwe's pitiful first innings before enforcing the follow on.