Graeme Smith [ Images ] held center stage for two hours at the Eden Gardens, taking the Indian bowling apart, piece by piece, and single-handedly saving the fourth one-day international from being a boring chase.
With the third match in Chennai abandoned due to rain, the visitors have taken an unbeatable 2-1 lead in the five-match series.
South Africa shot down the target of 189 runs in 35.5 overs, with Smith recording the highest score at the ground and Andrew Hall [ Images ] staying unbeaten on 48.
Earlier, Shaun Pollock [ Images ] and Hall claimed three wickets each as South Africa bundled India out for a paltry 188 after putting them in to bat.
Pollock (3 for 25) started the destruction, reducing India to 23 for three, while Hall (3 for 36) added to India's misery with two quick wickets at the end, as the hosts were shot out in 45.5 overs.
Yuvraj Singh [ Images ] and Mohammad Kaif provided some cheer to the huge crowd with an 81-run partnership for the sixth wicket.
Yuvraj, riding on his good form, hit 53 from 78 balls while Kaif rotated the strike brilliantly to score 46 from 63 balls.
The problem with extravagant experiments is that they can sometimes look inexplicable when they don't pay off.
Persisting with their rotation policy, the Indians opened the innings with Gautam Gambhir [ Images ] and Irfan Pathan [ Images ]. The Baroda player was successful as a pinch-hitter at number three and came out with a clear directive from the team management to go after the bowling.
But the move came unstuck, as Pathan chopped the second delivery he faced onto the stumps. Shaun Pollock pitched the ball outside the off-stump and Pathan tried to cut it past point, but it came off an inside-edge and one bounce into the stumps. (2-1, 0.3).
Pollock is always a dangerous bowler in the early overs and though the Eden Gardens pitch did not have lot of bounce, he made up for that with accurate seam movement.
Gambhir brought the huge crowd some cheer as he slammed two fours past point, even as Sachin Tendulkar [ Images ] struggled to overcome the stranglehold of the South Africa bowlers.
The master batsman's record-breaking 357th outing at the wicket came to a tame end when he was caught behind off Pollock on two from 15 balls. The ball moved away slightly from the batsman and carried a faint edge to wicketkeeper Mark Boucher [ Images ]. (14-2, 4.3)
Former South Africa captain Pollock then came in to pick the wicket of Gambhir in the next over. The left-hander, on 11, edged a ball moving away from him to Graeme Smith at first slip. (23-3, 6.5).
Sehwag opened his account with a fluent drive through cover and continued in the aggressive vein despite the early collapse. The Indian vice-captain, coming in at number four only for the third time in his 138-match career, hit 30 from 19 balls, with the help of six boundaries, and seemed well on his way to getting India out of the mess.
The Delhi [ Images ] batsman was severe on Andrew Hall, cracking three fours off him. But the bowler managed to get the better of Sehwag. Having lofted Hall to the mid-wicket fence, Sehwag tried to drive the next delivery away from his body and ended up edging to the wicketkeeper. (49-4, 11.2).
While Rahul Dravid [ Images ] took time to get the eye in, Yuvraj Singh looked in good touch and stroked the ball beautifully.
After the initial spell from Pollock and Andre Nel [ Images ], medium pacers Hall and Charl Langeveldt kept the Indian batsmen in check on the grassy wicket. They kept the seam upright and got enough movement from the track to keep the batsmen guessing.
Dravid was done in by a Langeveldt delivery, pitched full and keeping straight. The Indian captain stepped across and played down the wrong line only to see his off-stump out of the ground. (71-5, 18.2).
Yuvraj and Mohammed Kaif then got together to rebuild the Indian innings. With the old comrades-in-arms at the wicket, there suddenly was a lot of activity and excitement. Not only were they stealing the singles from the South Africans, the boundaries were also coming freely.
After the first 20 overs even the conditions eased up for the batsmen. South Africa also suffered from a monotonous attack, as Smith replaced Hall with Jacques Kallis [ Images ], another medium-pacer.
The ace all-rounder looked off-colour and conceded 17 runs from three overs without taking a wicket. Smith only brought on off-spinner Johan Botha [ Images ] belatedly in the 30th over.
Kaif and Yuvraj are masters at exploiting the gaps in the field and the comfortable pace from the bowlers only helped their cause. As initial pressure eased off, the batsmen were also capable in spoiling the rhythm of the bowlers and made them bowl to their strengths.
The left-hander was particularly severe on anything pitched slightly wide off the off-stump, timing the ball to perfection to the boundary. He hit five boundaries between third man and cover and picked 31 runs in the area.
The pair took India past 100 in the 26th over and then raced to 127 for five at the end of 30 overs.
Their partnership of 81 runs off 83 formed the backbone of the Indian innings, and at 151-5 from 35 overs India was on for a late surge.
Yuvraj brought up his 20th ODI fifty off 73 balls, with the help of seven fours. Of the 19 half-centuries he hit previously, India had won the game 16 times.
Botha broke the fruitful sixth-wicket partnership when he snapped Yuvraj leg before wicket on 53 off a quicker delivery. The left-hander tried to turn the ball on the leg-side but failed to make contact and was trapped in front of the stumps. (152-6, 35.3).
South Africa regained control of the game when Nel claimed Kaif four overs later on 46. The bowler got the wicket in his penultimate over when Kaif pulled straight to mid-wicket. (167-7, 39-2).
Despite India's hardest hitter Mahendra Singh Dhoni [ Images ] at the wicket, India failed to up the scoring rate.
The last three wickets fell in a heap, in the space of one run.
Ajit Agarkar [ Images ] (11) was the first to go, bowled by Kallis. (187-8, 44.4). Dhoni failed to add a single boundary to his name and was out on 14, caught at long-on by Botha off Hall. (187-9, 45.2).
Harbhajan Singh [ Images ] was the last man to fall, trapped leg before wicket by Hall.
Pollock and Hall ended with three wickets each to bundle out India for 188 in 45.5 overs.
If it wasn't for the stand between Kaif and Yuvraj, India's position would have been worse. A total of 188 though may prove too tight to bowl at under lights.
South Africa innings:
South Africa captain Graeme Smith started in a rush. He opened his account with a big swing down to the mid-wicket fence and set loose a flurry of boundaries to make the total look smaller than it was.
Not only did the total of 188 give too little for the Indians to bowl at but it also swelled the visitors' confidence dramatically.
The onus was on the Indian bowlers to get the early breakthrough, but disappointing opening spells from Irfan Pathan and Ajit Agarkar saw South Africa grab the advantage. The Proteas raced to 24 for no loss at the end of three overs, with Smith looking in a killing mood.
Though Pathan and R P Singh, who came first change, leashed the scoring rate after the six-over outburst, they hardly troubled the South Africa batsman.
Andrew Hall seemed content at letting Smith do all the damage, and the left-hander did it in style.
Smith brought up his fifty with another drive past backward point at a run-a-ball, and with the help of eight boundaries. The pitch that seemed to hold demons while India were batting proved to be a cakewalk for the South African captain. He trusted the bounce in the pitch and was given enough room by the Indian pacers to free his arms.
That India sprayed the ball on either side of the wicket was reflected in Smith's major scoring areas: behind point and the arc between square-leg and mid-wicket.
India captain Rahul Dravid introduced Harbhajan Singh into the attack in the 12th over. The off-spinner slowed down the batting momentum as the batsmen played him vigilantly early on. Though the wicket was on the slower side, it hardly afforded any turn for Harbhajan to play with.
Smith thwarted Harbhajan's hold by stepping down the track and hoisting straight over the bowler's head for six.
Even employing spin at both ends in the 17th over, when Murali Kartik [ Images ] came in as the supersub for Gautam Gambhir, did not help dampen the South African spirit. Kartik was quickly taken off for two boundaries each by Smith and Hall, as the Indians slumped to a hopeless situation.
India's only chance came in the 24th over with Smith on 77 and the team total on 99. The 24-year-old edged Harbhajan to wide first slip but Dravid spilled the catch.
Smith then welcomed Agarkar, who had gone for 25 runs in his first four overs, for the second spell with a hat trick of boundaries. The last of which set a record for the best opening partnership at the Eden Gardens.
The previous best was a stand of 120 between Raman Lamba [ Images ] and Kris Srikkanth for India against Pakistan in 1989.
With the game out of India's reach now, Smith's century remained the only interest.
Just like he had reached his fifty, he logged in his fifth ODI century with a cover-drive. He leaned into the delivery from Harbhajan and the ball raced down to the fence. Interestingly, he brought up his hundred at an exact run a ball and the same number of boundaries-eight (one six and seven fours).
Smith was playing the ball late and almost knew all the gaps in the field by heart. On completing his hundred, he didn't want to waste too much time in cruising South Africa to victory.
With such an overwhelming display at the other end, Hall seemed an invisible entity in the scheme of things. But he played a remarkable innings and like most unsung heroes just fell short of a landmark score.
As Smith lofted Sehwag over mid-on for the winning runs, Hall sprinted up the skipper to savour the winning moment; his score showing 48 not out.
Not many at the ground would have given India a chance after their disastrous batting performance, but Smith single-handedly dismantled the Indian attack to help the tourists score a crushing victory and take an unassailable lead of 2-1 in the five-match series, with the last match scheduled to be played in Mumbai [ Images ] on November 28.
Smith finished with his career-best score of 134 not out. It was also the highest individual score in ODIs at the Eden Gardens.