Spinner Tabraiz Shamsi (4-33) and paceman Kagiso Rabada (4-41) were the stars for South Africa as the hosts battled to recover from slumping to 36-5. Kusal Perera (81) and Thisara Perera (49) shared a sixth-wicket stand of 92, but Sri Lanka were dismissed for 193 after just 34.3 overs.
The Proteas lost early wickets but skipper Faf du Plessis (47) and Jean-Paul Duminy (53 not out) guided South Africa to their victory target, reaching 196 for five with 114 balls of their 50 overs still remaining.
Watch the highlights of the first ODI below.
