South Africa wrap this up in three days by an innings and 90 runs. It's their biggest win against India in India - the earlier record was an innings and 71 runs in Bangalore in 2000.
It's also India's fourth-largest defeat at home (among innings defeats), and their worst in nearly 50 years - in 1959 Australia beat them by an innings and 127 runs in Delhi.
It's also India's first innings defeat since the 2001 Colombo (SSC) Test against Sri Lanka.
This will go down as one of the costliest tosses to lose. Kumble gambled by sending his batsmen in and what resulted was a carnage. India's 76 was their second lowest in a Test at home. South Africa started well, suffered a jolt in the middle before Kallis and de Villiers got together and ground the Indians to dust. de Villiers compiled his maiden double ton, Kallis his 30th ton and there was no looking back.
Here's Anil Kumble at the post-match presentation: "It was difficult to come back after getting bowled out for 76. They took the game away from us. We have been in this situation before. I thought the effort from our bowlers was 100%. We will bounce back."
Graeme Smith: "This was the perfect Test match for us. We dominated from the start. It was hard work for the bowlers today on a heavy outfield. It's been fantastic for AB and Kallis. The guys know we've got one more game to go. They've been focussed throughout the series."
de villiers is the Man of the Match: "I'm just over the moon. Having Kallis around was a good calming effect, especially when I was in the 90s. I enjoyed playing here, and the Ahmedabad fans have been great. Just the perfect Test for us."
South Africa have avenged their defeat at the same venue 12 years back. Coincidentally, the pitch was the topic of discussion there as well. My prediction is that the Kanpur pitch will turn from the third over. Expect three spinners. India are under pressure and there could be a few changes to the bowling attack for the next Test.
Thanks for your company. I least expected this game to finish so quickly. Thanks for the mails. Do join us for the Kanpur Test, starting April 11. On behalf of Jamie, Dileep and Binoy, this is Kanishkaa signing off. Cheers!
Ntini comes on to replace Steyn, it's getting darker
Another half hour extension in play, 6.12 will be the cut off time now
Jamie says: "You'd have thought this was Durban, not Ahmedabad, the way the press box stood to cheer the fielder on as he settled under the ball, but the drop has drawn curses from many here."