India took a firm grip in the Kolkata Cricket Test against South Africa. At stumps on the third day of the second cricket test today, the hosts consolidated their position by extending their first innings lead to 347 runs against the visitors. V. V. S. Laxman and skipper Mahendra Singh Dhoni slammed centuries making use of the lacklustre feilding by the visitors. Laxman scored 143 runs while Dhoni made 132. India declared their first innings at 643 for 6. 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. Earlier Sehwag scored 165 runs while Tendulkar made 106 yesterday.South Africa were 6 for no loss in their second innings as match was called off early due to bad light. The scores so far : South Africa-296 and 6 without loss; India-643 for 6 declared.