VVS Laxman (143) and Mahendra Singh Dhoni (132) slammed sparkling unbeaten centuries to compound South Africa's misery as India took a stranglehold of the second and final cricket Test with a mammoth 347-run first innings lead in Kolkata on Tuesday.

Laxman notched his 15th Test ton while Dhoni recorded his fourth, as the hosts piled a monumental 643 for six, their highest total against South Africa, before declaring their first innings about half an hour before close of play on the third day.

The visitors got to face just five balls and were six for no loss before bad light forced play to be stopped early on a day completely dominated by the home team.

Laxman and Dhoni gave a fine exhibition of strokeplay as they stitched a record 259-run partnership for the seventh wicket to put India in a commanding position from where they can push for a series-levelling victory.

With two days left and the Eden track expected to deteriorate, the Proteas are faced with a herculean task to save the game.

Both the experienced batsmen paced their innings brilliantly. The vociferous crowd at the Eden was treated to some scintillating strokeplay for the second day running as Laxman and Dhoni toyed with the clueless South African bowlers to consolidate India's position.

The Proteas had to take some of the blame for finding themselves in such a position as they dropped a few catches  and the bowlers also lacked the penetration after the second new ball wore out.

If India win the Test, they will retain their number one position in the ICC Test rankings. However, if the South Africans draw the match and clinch the series 1-0, they will dislodge India from the number one position.

Laxman was slow in his approach and had luck on his side when he edged one to the left of an outstretched AB de Villiers who failed to pouch it.

With local hero and former captain Sourav Ganguly in the stands, Laxman completed his century to continue his love affair at the Eden, where he played his best knock of 281 against Australia in 2001.

Dhoni joined Laxman in the middle for the seventh wicket as India continued scoring briskly, taking a 100-run lead over South Africa in the 93rd over.

Dhoni was lucky when on 27, as Kallis failed to get hold of the ball at first slip and Harris shouted in frustration, summing up the agony of South Africa. 

The pair accelerated the pace of scoring after notching up their centuries.

Resuming at the overnight score of 342 for five, the hosts lost night-watchman Amit Mishra (28) before Laxman and captain Dhoni virtually batted the visitors out of the contest.

The day began with Mishra hitting a quick-fire 38-ball 28 to put on a 48-run sixth wicket partnership with Laxman.

Dropped on five by Jacques Kallis in the slip, Mishra took the attack to the Proteas camp.

With Laxman displaying control at the one end, he took on the pace of Steyn and the slow spin of Harris to help India build on the lead.

Hoping for some reverse swing from Kallis, Smith delayed taking the new ball by four overs as Mishra played with aggression.

Mishra once again got a life when he was dropped by Smith (short extra-cover) while on 25.

Mishra's innings was ended by pacer Dale Steyn in the very next over when he was caught by Kallis at the second slip.