Kolkata:An unbeaten century by Graeme Smith propelled South Africa to a 10-wicket victory over India in the fourth one-dayer at Eden Gardens in Kolkata. After bowling out India for a paltry 188, the South Africans comfortably reached their target with 14.1 overs left, getting an unassailable lead in the series. For the Indian bowlers, 188 was too small a target to defend, and Smith and Hall spared none of the bowlers. Ajit Agarkar was particularly expensive, conceding 41 runs in his five-over spell. Smith's innings of 134 included 20 hits to the boundary and a six. This was the young South African captain's fifth one-day century. Put in to bat first by the Proteas, India never could settle down after Shaun Pollock ripped through the top order. In the end, the Boys in Blue managed to score only 188 runs, before they were bowled out. Yuvraj Singh and Mohammad Kaif did put up a 81-run partnership for the sixth wicket but the rest of the batsmen floundered. Yuvraj top-scored for India with 53, his 20th ODI fifty. Top order collapse Earlier, Shaun Pollock struck three early blows and then South Africa stepped up the attack, reducing India to 71 for 5. Even Sachin Tendulkar and Rahul Dravid failed to face the South African onslaught. But Yuvraj and Kaif then stood firm, guiding the Indian innings past the 150 run mark. Yuvraj scored 53 off 78 balls, with seven boundaries in his innings. Pollock swept through the Indian top order, beginning by dismissing Irfan Pathan, sent in to open the innings, in the first over of the match. Pathan was out for a duck. Pollock followed it up with the prized wicket of Sachin Tendulkar (2), caught behind for two in the fifth over of the match. Gautam Gambhir fell in Pollock's next over, caught at second slip by skipper Graeme Smith for 11. Virender Sehwag played some scintillating shots in his 20-ball 30, but he was caught behind by Mark Boucher off Andrew Hall in the 12th over. For a moment, it seemed Rahul Dravid and Yuvraj Singh would resurrect the Indian innings, but Dravid was clean bowled for six runs, off the bowling of Charles Langeveldt. Yuvraj, Kaif fight back Yuvraj and Kaif put up a fighting partnership, but India suffered another setback when Yuvraj (53) was dismissed leg before wicket in the 36th over by Johan Botha. Mahendra Singh Dhoni then joined Kaif at the crease, but then Kaif, while trying to hit Andre Nel, was caught by Graeme Smith for 46. Dhoni added 14 runs, but he was caught by Johan Botha near the boundary line as Dhoni tried to lift a delivery from Andrew Hall. The tailenders then departed one after the other, and India were bowled out with 4.1 overs to spare. Teams:India: Rahul Dravid (Captain), Virender Sehwag, M S Dhoni, Sachin Tendulkar, Yuvraj Singh, Mohammad Kaif, Ajit Agarkar, Irfan Pathan, Harbhajan Singh, R P Singh, Gautam Gambhir. Supersub: Murali Kartik South Africa: Graeme Smith (captain), Mark Boucher, Jacques Kallis, Shaun Pollock, Justin Kemp, Ashwell Prince, Andre Nel, Andrew Hall, Charles Langeveldt, Albie Morkel, Johan Botha. Supersub: Robin Peterson.