South Africa have extended their record winning run in one-day internationals to 13 matches courtesy of a 40-run victory over Sri Lanka in Cape Town.

The hosts, who had already sealed the five-match series by winning the opening three matches, remain on course for a series whitewash having cruised into a 4-0 lead.

South Africa won the toss and elected to bat first, but their innings got off to a shaky start when Hashim Amla was dismissed for just one run, leaving his side 3-1.

However, Quinton de Kock and Faf du Plessis built a 100-run partnership to overcome the early setback before the former was eventually dismissed for 55.

Any Sri Lankan hopes that De Kock's dismissal would swing the momentum back in their favour were quickly crushed, though, as Du Plessis went on to build an even bigger partnership with AB de Villiers, who hit 64 from just 62 deliveries to register back-to-back half-centuries for the first time since October 2015.

Du Plessis was the star of the show, though, eventually bowing out with 185 runs from 141 balls - the second-highest ODI score in South Africa's history.

The hosts set a target of 368 to win - a record at Newlands - but Sri Lanka made an encouraging start in their efforts to chase it down with Niroshan Dickwella and Upul Tharanga putting together an opening partnership of 139.

Dickwella was dismissed for 58 to end that, but Thuranga went on to reach his century in the fourth-fastest time in Sri Lankan history before eventually being dismissed for 119.

There was also a score of 58 for Dharshanapriya Weerakkody as the tourists reached 307-4, but a collapse in the tail saw them lose their final six wickets for just 20 runs as South Africa stormed to victory.