London - Sri Lanka decided to make use of the overcast conditions as they elected to bowl first after winning the toss in their opening Champions Trophy fixture against South Africa at The Oval on Saturday.
LIVE: Proteas v Sri Lanka
However, they face the Proteas without talismanic captain Angelo Mathews after he failed a fitness test on the calf muscle he injured in a warm-up match with New Zealand - Upul Tharanga leads the side in his place.
South Africa are firm favourites to win the contest having whitewashed Sri Lanka 5-0 in a bilateral series between the countries in January.
South Africa - who came into the tournament on the back of a 2-1 series loss to England - are the world's number one ranked team while Sri Lanka are seventh.
South Africa: AB de Villiers (captain), Hashim Amla, Quinton de Kock (wkt), JP Duminy, Francois du Plessis, Imran Tahir, David Miller, Morne Morkel, Chris Morris, Wayne Parnell, Kagiso Rabada
Sri Lanka: Upul Tharanga (captain), Dinesh Chandimal, Niroshan Dickwella (wkt), Nuwan Pradeep, Asela Gunaratne, Chamara Kapugedera, Suranga Lakmal, Lasith Malinga, Kusal Mendis, Kusal Perera, Seekkuge Prasanna.