Quinton de Kock scored 104 as South Africa swept past Sussex by 66 runs in the opening one-day match of their England tour on Friday.
In a match reduced to 32 overs because of rain, De Kock scored 104 off 78 balls while Wayne Parnell and JP Duminy struck half-centuries as South Africa ran up a formidable 289 for four.
Sussex were never in the chase after losing openers Chris Nash, the captain, and Luke Wells for ducks in the first over bowled by seamer Kagiso Rabada.
De Kock, 24, who missed the Indian Premier League after suffering a finger injury in New Zealand in March, retired after striking five fours and seven sixes.
He and Parnell put on 121 for the first wicket before Parnell hit 61 off 42 deliveries with seven fours and three sixes.
Duminy scored 68 off 46 balls, hitting successive sixes off spinner Danny Briggs.
South Africa have another warm-up game at Northampton on Sunday before facing England in the opening ODI at Headingley on Wednesday.