|Smiles all round for Dhoni and Laxman, as India battle to level the series [AFP]
Vangipurappu Laxman and Mahendra Singh Dhoni hit magnificent centuries to put India in sight of a series-levelling victory over South Africa in the second and final Test in Kolkata.
Laxman carved out an unbeaten 143 and Dhoni struck 132 not out as the hosts declared their first innings at 643-6, a lead of 347.
The last recognised batting pair put on 259 in an Indian record seventh wicket stand after the hosts resumed on 342-5, 46 runs ahead of South Africa (296), who had rallied with three late wickets on Monday.
South Africa were six for no loss in their second innings when play was called off due to bad light.
The tourists delayed taking the second new ball for four overs in gloomy morning conditions that allowed the overnight pair of Laxman and nightwatchman Amit Mishra (28) to settle down as India went on to post their highest innings total against South Africa.
Rangy fast bowler Morne Morkel had Mishra caught at slip with the new ball but the nightwatchman had by then put on a further 42 runs with Laxman, who missed the opening Test due to injury.
South Africa had clawed back into the contest the previous evening after centuries by Virender Sehwag (165) and Sachin Tendulkar (106) put India well in control of the match they must win to retain the number one ranking.
India first innings (342-5 overnight)
G Gambhir run out 25
V Sehwag c Prince b Duminy 165
M Vijay c de Villiers b Morkel 7
S Tendulkar c Kallis b Harris 106
V Laxman not out 143
S Badrinath b Steyn 1
A Mishra c Kallis b Morkel 28
M Dhoni not out 132
Total (six wickets dec; 153 overs) 643
Fall of wickets: 1-73 2-82 3-331 4-335 5-336 6-384.
South Africa second innings
G Smith not out 5
A Petersen not out 1
Total (no loss; 0.5 over) 6
To bat: H Amla, J Kallis, AB de Villiers, A Prince, JP Duminy, D Steyn, W Parnell, M. Morkel, P Harris.
Bowling (to date): Zaheer 0.5-0-6-0.
South Africa are bidding to win their first Test series in India for a decade, which would also reclaim the top ranking after the tourists won the opening Test in Nagpur by an innings.
Laxman, who passed 7,000 Test runs, hit 16 fours as he reached his 15th Test century. He enjoyed some luck when he was dropped by stand-in wicketkeeper AB de Villiers on 23 and JP Duminy at backward point on 48.
Dhoni offered a difficult chance to Jacques Kallis at slip off left-arm spinner Paul Harris but recovered to plunder the attack for 12 fours and three sixes as he reached his fourth Test hundred.
It was only the second occasion that four Indian batsmen have scored centuries in a single Test innings.
Dhoni hit two successive sixes off spinner JP Duminy as he stepped up the tempo before effecting the declaration with 11 overs still remaining before close of play.
South Africa failed to take at least five difficult chances on the field on the third day alone, allowing India to prosper as the hosts slowly regained control of the Test.
India are trying to avoid their first series defeat at home since 2004 to Australia after having lost their first Test in almost two years at Nagpur last week.