Sa vs india
Du Plessis 50 fails to keep Proteas out of Test trouble
The Proteas were 136 for six at lunch in response to India's 601-5 declared, with Du Plessis on 52 and Senuran Muthusamy on six.
Left-hander Elgar, who started the day on 27, reached his hundred with a six off Ravichandran Ashwin in the second session as he let out a big roar in Visakhapatnam.
Resuming on 90/2 and a second innings lead of 118, the Proteas were looking to press home the advantage and set India an enormous target, with AB de Villiers striking the ball.