Captain Quinton de Kock hit a brilliant century when South Africa struck a winner against world champion England at the opening one-day international tournament in Newlands on Tuesday.
After going into the bat, England overcame a high-level wiggle and prevailed with a well-built Joe Denley 87er at Lord's first ODI appearance since winning the World Cup last July for eight of fifty overs.
De Kock (107) and Temba Bavuma (98) put 173 in for the second wicket when South Africa scored 259 for three to secure the win with 14 balls.
The second ODI will be held in Durban on Friday. The three-game series ends on Sunday in Johannesburg.
England have rested Ben Stokes and Jos Buttler for this series with just five players who made it to the World Cup final last year. Seaman Chris Woakes is the only survivor of the bowling attack.
South Africa lost Reeza Hendricks to wicket keeper Jonny Bairstow before Woakes for six at the start of his chase.
But De Kock and Bavuma played risk-free cricket, turned the stroke excellently and reached the limits on occasion.
De Kock reached his 15th ODI century in 106 balls before being overwhelmed by Joe Root's sideline.
Bavuma, who was only playing in his third ODI, was caught just outside the goal of Chris Jordan, who was only two runs ahead of the first ton he deserved, but played a crucial role in winning the game.
England started the next round brilliantly, scoring 51 points in the tenth game with no loss, but lost five goals for another 57 runs when their top order collapsed.
Jason Roy (32) looked good before he ranged against spinner Jon-Jon Smuts against Hendricks and Jonny Bairstow (19) fell on Andile Phehlukwayo.
Rassie van der Dussen hit Root (17) with a shot from Rassie van der Dussen (11) and Bavuma with a slip from Tabraiz Shamsi (3-38). The home team was on top.
Shamzi also picked up the goals of debutant Tom Banton (18) and Sam Curran (7) to tumble out of England, but Denley and Woakes (40) bet 91 on the seventh wicket to help guests Chasing to score for the home team.