South Africa's Hashim Amla posted his first test double century to flatten India's insipid attack on the second day of the opening cricket test in Nagpur.
The 26-year-old remained unbeaten on 215 after helping South Africa reach a commanding first-innings score of 477 for five at tea at the VCA Stadium.
The number three batsman shared in a 108-run fourth wicket stand with AB de Villiers (53) after taking his overnight partnership with Jacques Kallis (173) to 340 to put the tourists in the driver's seat.
Amla's marathon effort enabled South Africa to recover after losing both openers for six runs and has offered the chance to set up a rare series victory on Indian soil.
Kallis was denied a first double century when caught at short leg by Murali Vijay off off-spinner Harbhajan Singh after the tourists resumed at 291-2.
Amla, who has given South Africa a platform to wrest back the top ranking from India, stroked 20 fours in his brilliant knock.