South Africa has won the first one day international against Sri Lanka in the three match ODI cricket series that started in Colombo today.Earlier, opener Hashim Amla smashed 109 off 130 balls to steer South Africa to a formidable 304-5 at R Premadasa stadium in hot humid conditions.In reply, hosts got a healthy start with in form star batsman Kumar Sangakkara scoring 88. But soon after his departure Sri Lankan middle order collapsed and folded up at a mere 229 in the 41st over, giving the Proteas a morale-boosting 75 run win.The second match of the series will be played at Palekelle Stadium in Kandy on Wednesday.