Second Test, Kolkata, day two (close):
India 342-5 v South Africa 296
Tendulkar has made eight more Test tons than nearest rival Ricky Ponting
India closed day two of a fluctuating second Test against South Africa in Kolkata with a lead of 46 at 342-5.
South Africa lead the two-match series 1-0 and would depose India at the top of the rankings by avoiding defeat.
They added an extra 30 with their final wicket pair to finish on 296, but were soon trailing as Virender Sehwag and Sachin Tendulkar shared a superb 249.
Sehwag hit 23 fours and two sixes in 165 while Tendulkar made his 47th Test ton, but they fell in successive overs.
After Morne Morkel and Wayne Parnell had plundered two boundaries apiece to take South Africa within a whisker of 300, Zaheer Khan wrapped things up in his opening over, trapping Parnell with a clear lbw.
Sehwag and Gautam Gambhir then gave India a flying start, rattling up 73 in barely nine overs before Sehwag changed his mind about a second run while Gambhir was in mid-pitch, leading to him being run-out.
Sehwag had been in particularly ruthless mood, with three successive fours off Dale Steyn in the third over of the innings and three more in an over from Morkel.
Sehwag gave his side a pulsating start with some scintillating strokeplay
When he thrashed left-arm seamer Parnell through the covers for four and upper-cut him for six two balls later the dashing Indian opener had made 39 from 20 balls.
He needed six from two balls to set the fastest fifty in Test cricket - a record many would be surprised to learn is held by South Africa's Jacques Kallis - but was briefly becalmed.
Murali Vijay was peppered with some short deliveries before eventually being superbly caught by wicketkeeper AB de Villiers, diving to his right off Morkel, who then fired Tendulkar's opening delivery in at 91mph only to see the little master nonchalantly tuck it away for a single.
Sehwag was then put down on 47 by JP Duminy at slip off Morkel and the opener went past the fifty mark from 41 deliveries as India struggled somewhat to the lunch interval at 97-2.
The runs soon began to flow again and the opener hit two fours in an over off Steyn soon after the resumption and swept slow left-armer Paul Harris for six over mid-wicket.
Tendulkar maintained a steady scoring rate, whipping Morkel wristily through the leg-side for successive boundaries, while Sehwag reached his 19th Test century in suitably fine style, carving Parnell to the point boundary.
All but 24 of his first 100 runs came in boundaries but he was finally dismissed by Duminy in his first over, the spinner flighting one from round the wicket that was thumped low to cover.
Tendulkar, having passed 6,000 Test runs in India alone, edged a drive at a flighted ball from Harris and was well taken at slip.
Subramaniam Badrinath was bowled by a superb Steyn off-cutter that knocked back the off pole and VVS Laxman flashed at one off Harris that flew past slip for four, before bad light ended proceedings for the day, with the match fascinatingly poised.