South Africa have reached 278-5 at lunch on day three against Zimbabwe.
The visitors go into lunch 22 runs ahead of their opponents after 113 overs.
The South Africans started off the day on 202-4, losing their only wicket just before lunch.
Francois du Plessis missed out on his century by two runs when he was caught by Regis Chakabva off a Sean Williams delivery.
Quinton de Kock remains not out and is 25 runs off his own century after a solid batting performance.