South Africa were bowled out for their lowest-ever Test total against India as 20 wickets fell on a dramatic second day of the third Test in Nagpur.
The Proteas were skittled for just 79 - which also represented their worst score since readmission to international cricket in 1991 - as only JP Duminy's 35 saved them from further embarrassment.
They now face the likelihood of losing their first away Test series in nine years.
India's spinners again ran rampant, on a VCA Stadium wicket offering plenty of assistance, as they maintained their stranglehold over the Proteas batsmen with all 10 wickets. Ravichandran Ashwin led the way with five for 32.
The drama did not there, however, as India were then bundled out for 173 to remarkably leave the tourists with an outside hope of a series-levelling win.
South Africa cautiously moved to 32 for two by stumps in pursuit of 310, a considerable target in the context of a low-scoring series.
Victory for India would give them an unassailable 2-0 series lead heading to the final Test at Delhi, which starts on December 3.
South Africa's highest score in four Test innings so far on tour is just 184, while 40 of the 42 wickets they have lost in the series have gone to the Indian spinners.
Hopes of reversing that trend were scuppered after only four overs of the day as South Africa, resuming their first innings on 11 for two, lost three batsmen for one run, including key pair Hashim Amla and AB de Villiers.
Ashwin had already struck in the first over of the day, when Dean Elgar chopped onto his stumps, when a series of ricochets ended up in the hands of Ajinkya Rahane after Amla attempted a sweep.
De Villiers followed for a duck when he was fooled by a combination of the wicket and the bowling of Ravindra Jadeja to offer a simple return catch off his leading edge.
South Africa were 12 for five and while the best partnership of the innings followed - 23 runs between Duminy and Faf du Plessis - the respite was hardly long-lasting as South Africa were dismissed in just 33.1 overs. Jadeja finished with four for 33.
That handed India a first-innings lead of 136 which was enhanced further as they progressed to 97 for two before suffering a collapse of their own.
South Africa leg-spinner Imran Tahir led the fightback with five for 38, while Morne Morkel's three for 19 proved the seamers had some role to play.
But the early runs from Shikhar Dhawan and Cheteshwar Pujara, scoring 39 and 31 respectively, had perhaps already steered India into clear water well before they were bowled out for 173.
That left South Africa with 14 overs to bat before the close and they lost Stiaan van Zyl, loosely pushing Ashwin to short cover, and nightwatchman Tahir lbw to Amit Mishra.