India have lost both their openers. After bowling out the Proteas for 265 on the first day, the hosts started their innings on Day 2. Virender Sehwag was the first one to go, he made just 8, before Dale Steyn sent him back leg before.
Wasim Jaffer was dismissed in similar fashion by Morne Morkel after he made 15, but that decision looked slightly doubtful.
Rahul Dravid and VVS Laxman are at the crease now. And though India have lost 2 wickets, this reamains an extremely crucial session that could well decide the fate of the series.
South Africa lead 1-0 in the series following their emphatic victory by an innings and 90 runs in the second Test in Ahmedabad. The opening match ended in a draw in Chennai.
India hardly felt the absence of skipper and ace leg-spinner Anil Kumble as specialist and part-time spinners halted South Africa's march towards a big total.
Kumble was ruled out after failing to recover from a groin strain, with Mahendra Singh Dhoni becoming the first wicket-keeper to lead India in a Test.
South Africa began strongly after winning the toss, with Smith putting on 61 for the opening wicket with Neil McKenzie (36) and 91 for the next with Amla.
The visitors' slide started in the afternoon session when they lost three wickets in the space of nine runs.
Left-handed Smith, who swept powerfully and used his feet well against spin, was the first to go when he was caught off his gloves by diving short-leg fielder Wasim Jaffer to become Yuvraj's victim.
The South African captain scored comfortably during his 134-ball knock, reaching his 22nd Test half-century with a six off Chawla and then hoisting Yuvraj for a second six. He also hit eight fours.
Amla also countered spin remarkably well as he patiently waited for loose deliveries during his eighth Test half-century before being bowled by Sharma in the afternoon.
India bounced back into the game when second-Test century-maker Jacques Kallis played a Harbhajan delivery on to his stumps after contributing one.
The Indian spinners continued to keep pressure on the batsmen, with A.B. de Villiers, Ashwell Prince, Boucher, Morne Morkel, Paul Harris and Dale Steyn falling in the closing session.
De Villiers, who cracked a maiden double-century in the last Test, mistimed a pull off Chawla and was caught by Sourav Ganguly at short mid-wicket while Prince was trapped leg-before by Sehwag.
India struggled for wickets only in the morning session as they could grab just one when Chawla had McKenzie stumped in his opening over.
McKenzie had been looking solid during his 57-ball knock before losing his patience. He stepped out to drive the leg-spinner but was beaten by the flight, with Dhoni completing an easy stumping.