Hambantota - South Africa beat hosts Sri Lanka by a convincing 32-run margin in a rain-shortened seven-over-a-side World Twenty20 group C match here on Saturday.Full scorecardThe Proteas were good with both bat and ball as their pacemen never allowed the Sri Lankan batsmen to chase a daunting 79-run target.Skipper AB de Villiers smashed two sixes and a boundary during his 13-ball 30 while Hamshim Amla (16) and Faf du Plessis (13) were the other main run contributors in a total of 78-4 after South Africa were sent in to bat.Sri Lanka were without their ace spinner Ajantha Mendis, who took 6-8 in their win over Zimbabwe, after suffering from a side strain.Heavy rain delayed the start by two and a half hours as a sell-out 35 000 crowd waited anxiously for action and although they got it late the fireworks in a shorter game gave them some consolation.Sri Lanka were never in the hunt, losing star duo Tillakaratne Dilshan (nought) and Mahela Jayawardene (four) in the first two overs.Dale Steyn was South Africa's best bowler with 2-10. Dilshan Munaweera and Kumar Sangakkara made 13 each.De Villiers said his team is ready for the next round."Beating Sri Lanka is nice because they are one of the top teams and now we are ready for the Super Eights, we didn't take anything for granted and it was nice to win," said the South African captain.Jayawardene said it was tough in a reduced match."It is always tough in a rain reduced match. We were without Mendis because we didn't want to take risk with important matches coming up," said Jayawardene. "We must improve our fielding."South Africa, who finished top of the group, and Sri Lanka qualified for the Super Eight rounds. Both had beaten Zimbabwe in their opening matches.Sri Lanka will be in group one of the Super Eights while South Africa will be in group two, regarded as the group of death with India, Australia and Pakistan likely to be the other teams.Brief Scores:South Africa 78-4 in seven overs (AB de Villiers 30); Sri Lanka 46-5 in seven overs (D. Steyn 2-10)Teams:Sri Lanka:Dilshan Munaweera, Tillakaratne Dilshan, Mahela Jayawardena, Kumar Sangakkara, Lahiru Thirimanne, Angelo Mathews, Jeevan Mendis, Thisara Perera, Nuwan Kulasekara, Rangana Herath, Lasith Malinga.South Africa:Hashim Amla, Richard Levi, Faf du Plessis, AB de Villiers, JP Duminy, Farhaan Behardien, Jacques Kallis, Albie Morkel, Johan Botha, Dale Steyn, Morné Morkel.