Hashim Amla's 159 allowed South Africa to post a first innings total of 540 in the first Test against India.
India openers Wasim Jaffer and Virender Sehwag shared an unbroken stand of 82 to reduce their side's deficit to 458 by the close of day two.
The Proteas used the first 62.5 overs on Thursday to extend their first innings from 304-4 to 540 all out.
Amla, on 85 overnight, hit three consecutive fours off Shantha Sreesanth's bowling to complete his fourth Test century from 173 balls during a morning session in which the tourists lost just one wicket, AB de Villiers (44) edging behind off Sreesanth (1-104).
Mark Boucher joined Amla in a 99-run, sixth-wicket partnership either side of lunch that cemented the tourists' position of dominance in the match.
Amla's superb 262-ball innings was brought to an end in mid-afternoon by a run out, but Boucher ploughed on in the company of Morne Morkel, neither wishing to miss the opportunity to collect some easy runs on an excellent batting surface in Chennai.
Boucher had reached 70 when he top-edged a slog-sweep off Sehwag's (1-37) occasional off-spin and was caught by Rahul Dravid, running back from slip.
Off-spinner Harbhajan Singh claimed the final three wickets - Morkel (35), Paul Harris (5) and Dale Steyn (15) - to finish with figures of 5-164.
Jaffer and Sehwag made good use of the final 21 overs by compiling a confident partnership of 82.
Sehwag lashed six fours and one six to finish on 52 not out from 61 balls - his 14th Test half-century - while Jaffer played a more sedate hand to close on 25 not out.