Virender Sehwag scored the fastest triple-hundred in Test cricket history as India battered the South African attack on day three of the first Test at Chennai.
Sehwag finished unbeaten on 309 as India piled up 468-1 in reply to the Proteas' first innings total of 540.
The 29-year-old, who made 309 against Pakistan at Multan in 2004, became only the third player to achieve the feat of two Test triple-hundreds, alongside Australian Don Bradman and West Indies' Brian Lara.
Sehwag raced to 300 off 278 balls, surpassing Australian Matthew Hayden's 362-ball effort when he scored a then world record 380 against Zimbabwe at Perth in 2003-4.
The Indian batsman lashed 42 fours and five sixes before nudging paceman Makhaya Ntini for a single to squareleg for his 300.
The Indian star did not offer a chance in an almost flawless innings of 292 balls, as the hosts put themselves in position to put some pressure on the Proteas over the final two days.
He was well supported by Rahul Dravid (65no) in an unbeaten second innings partnership of 255.
India started the day on 82 without loss and Sehwag put on 213 for the first wicket alongside Wasim Jaffer (73), before his fellow opener edged left-arm spinner Paul Harris to Jacques Kallis in the slips to give the tourists their solitary breakthrough.
Dravid then joined him and the man known as 'The Wall' lived up to his name, scoring 65 in 181 balls. In the process he took his career tally to 9,985 runs by stumps and needs only 15 more to become just the sixth batsman in history to complete 10,000 Test runs.
Sehwag's double ton off 194 balls was the third fastest in Test history after New Zealander Nathan Astle's 153-ball knock against England at Christchurch in 2001 and Sehwag's own 182-ball innings against Pakistan in Lahore in 2006.
The 55-Test veteran was at his best in the afternoon session when he scored 108 of India's 133 runs, as the South African bowling wilted in oppressively hot and humid conditions.
It was Sehwag's second successive three-figure score following a match-saving 151 in his last innings against Australia at Adelaide in January.
On Saturday he will be bidding to overhaul Brian Lara's Test record score of 400, with India set to bat past the tourists' total and have a dart at them on day five.