Tendulkar's epic ton gives India slender lead

(CNN) -- Sachin Tendulkar's 51st Test century left the decider between the top two rated nations on a knife edge after India took a two-run first innings lead over South Africa in Cape Town on Tuesday.

Tendulkar can scarcely have scored a more valuable ton as he battled a menacing home attack, led by Dale Steyn, on a helpful Newlands wicket.

By the close, South Africa had reached 52 for two in their second innings, losing captain Graeme Smith to Harbhajan Singh for 29, quickly followed by nightwatchman Paul Harris.

Tendulkar was eventually bowled by Morne Morkel for 146, having shared fine stands of 176 with Gautam Gambhir and 76 with Harbhajan, who was full of praise for the little maestro's efforts.

"It was a great day for Test cricket," said Harbhajan. "Sachin got another brilliant hundred and Steyn bowled brilliantly. You can't ask for more."

Tendulkar, who made his 50th Test ton in India's heavy defeat at Centurion, faced 313 balls during his stay at the crease and hit 17 fours and two sixes.

Gambhir, who fell seven short of his century, was one of three third day victims for Steyn, the world's number one ranked bowler finishing with five wickets for 75.

It left India with a narrow lead and the late wickets tipped the balance their way with series tied at 1-1.

Their win in Durban guaranteed they will remain world number one, but the real prize will be a rare series triumph in South Africa.