India were 221 four at tea on the third day, needing another 138 runs to avoid the follow-on after South Africa's imposing first innings total of 558-6 declared.

Sehwag had scored 109 before pace bowler Wayne Parnell claimed the prize wicket to improve South Africa's chances of winning the first of the two tests in the series.

Subramaniam Badrinath marked his test debut by reaching 56 not out and he was at the crease with last recognized batsman Mahendra Singh Dhoni (6).

Fast bowler Dale Steyn struck twice early to put India on the back foot after the hosts resumed at 25 without loss.

Steyn dismissed Murali Vijay for four and Sachin Tendulkar for seven in a fiery opening spell after Morne Morkel removed opener Gautam Gambhir, who failed to add to his overnight score of 12.

Sehwag batted with uncharacteristic patience to put on 136 for the fourth wicket with Badrinath, who batted with poise after starting tentatively.

Sehwag hit 15 fours to lift India before falling to a poor shot to be caught by JP Duminy in the covers to put the pressure back on India.

Gambhir, who had notched eight centuries in his previous 11 tests, fell to a beauty from Morkel that moved just a shade, the resulting edge thudding into wicketkeeper Mark Boucher's gloves.

It was the first ball that Gambhir faced in the morning and a big blow for India.

Steyn dismissed Vijay with one that cut back sharply as the batsman shouldered arms. The South African then enticed Tendulkar to nibble one to Boucher, who is approaching a record 500 dismissals in test cricket.

Hashim Amla hit an unbeaten 253 and Jacques Kallis struck 173 to put South Africa on top in their bid to record a rare series victory on Indian soil and reclaim their number one ranking from the hosts.