India have gained total control of the fourth Test with South Africa after bowling the Proteas out for 121 on day two in Delhi.
Having begun the day on 231-7, India added another 103 runs on Friday as Ajinkya Rahane recorded his fifth Test century, eventually being dismissed for 127 before the hosts were all out for 334.
South Africa needed a solid start and they got one thanks to Dean Elgar and Temba Bavuma, but after Elgar (17) went with the score on 36-1, the top order crumbled under pressure from Ravindra Jadeja, who struck three times in quick succession to reduce South Africa to 65-5.
AB de Villiers added a resilient 42, but South Africa could not cope with Jadeja, who ended with figures of 5-30, and the rest of the Indian bowling attack.
Just before the close of play, South Africa were all out for 121, but with three days of the match still remaining, India will return to the crease on Saturday having chosen not to enforce the follow-on.