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 4-289.
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.
Quick Single: 'I haven't quit Test cricket' says ABdV
For de Kock, the looming Champions Trophy that follows the series with England is forefront in his thoughts after a disappointing 2015 World Cup.
The wicketkeeper came into that tournament in Australia and New Zealand underprepared after tearing ankle ligaments, and was below his best.
But in the intervening two years he has cemented himself as a superstar, and just last week garnered an extraordinary five accolades at South African cricket's annual awards.
"I know Quinton is desperate to do well in one of these ICC events," Proteas coach Russell Domingo said.
"He'll probably be the first to admit that in the previous 50-over World Cup he probably didn't meet the expectations we placed on him.
"I'm sure he's got some points to prove in these type of events."
Quick Single: Big names in Australia A squad
The 24-year-old has already scored 12 centuries and 12 fifties in international 50-over cricket and alongside the likes of AB de Villiers, Hashim Amla and Faf du Plessis forms the basis of a stable South Africa top order.
"Our top six looks after themselves. It's about making sure we play the form allrounders going into the competition," said Domingo.
"We also need to find a way to play two spinners if we need
"Having Keshav (Maharaj) there gives us a bit more batting depth, but who are the allrounders we play with him? Do we play the frontline bowlers like Morne Morkel and Kagiso Rabada. We will mix and match a bit going into those first ODIs (against England)."
Quick Single: ‘Excitement machine’ Lynn must win spot
The Proteas opted for both spinners in Maharaj and Andile Phehlukwayo against Sussex, with allrounders Wayne Parnell and Dwaine Pretorius alongside quicks Rabada and Morkel.
And while the Proteas have never won a global cricket tournament, Domingo said there was no pressure on the side.
"We can take a lot of comfort that in a lot of our bilateral series like beating India in India in front of 60 000 people – we've done it," said Domingo.
"Having to beat New Zealand in Auckland to win a series, we've done that. Having to beat England in a final of a series, we've done that.
"There's a lot of comfort and confidence we can take from winning must-win games. I'm going there at ease knowing that this team has come through pressure situations in the last year and a half."
Champions Trophy 2017 Guide
Squads: Every Champions Trophy squad
Group A: Australia, New Zealand, England, Bangladesh.
Group B: India, South Africa, Sri Lanka, Pakistan.
26 May – Australia v Sri Lanka, The Oval
27 May – Bangladesh v Pakistan, Edgbaston
28 May – India v New Zealand, The Oval
29 May – Australia v Pakistan, Edgbaston
30 May – New Zealand v Sri Lanka, Edgbaston
30 May – Bangladesh vs India, The Oval
1 June – England v Bangladesh, The Oval (Day)
2 June – Australia v New Zealand, Edgbaston (D)
3 June – Sri Lanka v South Africa, The Oval (D)
4 June – India v Pakistan, Edgbaston (D)
5 June – Australia v Bangladesh, The Oval (D/N)
6 June – England v New Zealand, Cardiff (D)
7 June – Pakistan v South Africa, Edgbaston (D/N)
8 June – India v Sri Lanka, The Oval (D)
9 June – New Zealand v Bangladesh, Cardiff (D)
10 June – England v Australia, Edgbaston (D)
11 June – India v South Africa, The Oval (D)
12 June – Sri Lanka v Pakistan, Cardiff (D)
14 June – First semi-final (A1 v B2), Cardiff (D)
15 June – Second semi-final (A2 v B1), Edgbaston (D)
18 June – Final, The Oval (D)
19 June – Reserve day (D)