Tendulkar, who opens in one-dayers, smashed 200 not out off 147 balls to help India post 401-3 and take a winning 2-0 lead in the three-match ODI series.
South Africa were bowled out for 248 with AB de Villiers hitting a defiant 114 not out in the day-night match at the Captain Roop Singh Stadium.
Tendulkar hit 25 fours and three sixes in a spectacular innings that combined power, timing and enthusiasm with stunning strokeplay.
The 36-year-old batsman reached 200 with a single off Charl Langeveldt in the final over and the capacity crowd erupted in joy as Tendulkar looked skyward, kissed the crest of his helmet and raised his bat.
India lost opener Virender Sehwag for nine to left-arm seamer Wayne Parnell but Tendulkar, who extended his record number of one-day centuries to 46, proceeded to put on 194 for the second wicket with Dinesh Karthik (79).
Tendulkar reached his 100 with a single and moved to 150 with a four off Parnell as he took complete control of the attack after hitting a century in each of the two tests against South Africa in the drawn test series earlier this month.
Tendulkar holds the record for most runs in tests (13,447) and ODIs (17,598) and most centuries in tests (47) and ODIs.
Tendulkar put on 81 for the third wicket with Yusuf Pathan (36) and 101 for the unbroken fourth with Mahendra Singh Dhoni who blasted 68 off 35 balls with seven fours and four sixes at the stadium, which has short boundary lines.
Tendulkar moved past the previous record score of 194 jointly held by Pakistan's Saeed Anwar and Zimbabwe's Charles Coventry with a two off Parnell before recording the first double century since one-dayers were first played in 1971 and hugging Dhoni.
AB de Villiers hit his fifth ODI hundred but South Africa did not quite recover after losing their first four wickets for 83 to Indian seamers.
India won the first match by one run on Sunday and the final match will be played in
In St. John’s, Antigua and Barbuda, new West Indies coach Ottis Gibson has set earning the respect of his players as a major goal during their brief series against Zimbabwe.
Gibson was speaking at an official unveiling in the island of St. Lucia, where the West Indies Cricket Board (WICB) President Julian Hunte has an office. "I need to explain to them what they can expect from me first of all, and what I expect from them as the players," said Gibson.
"We need to have that contact time. They need to know they can trust me, but I also need to know I can trust them because it is a two-way street."
Gibson shocked the cricket World last month, when he gave up a comfortable job as England bowling coach to become the new coach of the beleaguered West Indies side that has flagged internationally for the last 15 years. The last few weeks would have given the former Barbados and West Indies fast bowler a reality check about the enormity of the challenge that faces him.
West Indies return to the Caribbean on Thursday from a horrific trip to Australia, where they failed to win any of the five One-day Internationals or two Twenty20 Internationals they played Down Under.
"The players will be low in confidence based on what happened recently in Australia," said Gibson.
"We have a game on Sunday in Trinidad, and the players get back on Thursday, so we literally have two days to get together as a group, for me to meet the team, and have some contact time with them." As bowling coach of England, Gibson is fully aware of how jarring criticism can be, but he was philosophical about handling the pressure that would come if he cannot halt the terminal decline of one of World cricket's brightest brands.
"I don't know if you can ever be mentally prepared for criticism," he said. "I know it is going to come.
"It is going to be a lot of work to start winning again. A lot of work goes into actually winning anything. I am committed to that work, and if we get the preparation right, there is no reason why we can't start winning again." West Indies face Zimbabwe in a single Twenty20 International this coming Sunday at Queen's Park Oval in the Trinidad & Tobago capital.
They then tackle the Zimbabweans in five ODIs which will be followed by the Twenty20 World Cup in the Caribbean, starting in April, and then three Tests and five ODIs against South Africa, starting in May.
