Sri Lanka won the toss and put their opponents in to bat and watched them rack up 338/7 without any real pressure.
There were a few moments throughout the South African innings where it looked as if they could put on a massive score, but set batsmen falling at regular interviews stopped them from really pushing on.
The most explosive stay at the crease in the South African innings came from their captain, Faf du Plessis. His 88 from 69 balls looked to have set a platform for a total in excess of 350 but three wickets falling for the addition of just 53 runs in the middle slowed things down somewhat.
Contributions at the end from JP Duminy (22), Andile Phehlukwayo (35), Dwaine Pretorius (25 not out) and Chris Morris (26 not out) saw South Africa post a total that was easily defended, but they will feel they left runs out in the middle.
Quinton de Kock was not given a game in Cardiff, with Aiden Markram and Hashim Amla opening in his absence. Markram went for 21 fishing at a wide one from Suranga Lakmal but Amla made his way to a fluent 65 (61). There were quite a few trademark Amla flourishes in an innings that contained nine fours.
When Sri Lanka began their innings there was an immediate breakthrough for Lungi Ngidi who bowled with real pace, despite last playing in March having had a long lay-off with a side strain. He took a wicket with the second ball of the Sri Lankan innings when Kusal Perera pushed at a ball just back of a length and was caught in the covers by David Miller.
Ngidi repeated the trick with the first ball of his second over when he induced an uppish drive from Lahiru Thirimanne, which was caught in the same spot by the same fielder.
The best Sri Lankan batsman was their captain, Dimuth Karunaratne, who made 87 from 92 balls, but with no-one able to play shots around him the required rate steadily rose. A stand for the fourth wicket worth 98 kept Sri Lanka in the hunt, but when he fell, the speed with which Sri Lanka needed to score increased further.
A steady half century from Angelo Mathews prevented this from being a massive defeat, but Sri Lanka were never really in this match. The South Africans will feel that their batsmen got a decent run and that their bowlers looked incisive, with four wickets for Phehlukwayo being a big boost ahead of the World Cup starting next week.
Africa News Agency (ANA)