Heinrich Klaasen has scored a 61-ball century, as South Africa posted 399 and then bowled England out for 170 in 22 overs to claim a massive 229-run victory in their Cricket World Cup pool stage clash at Mumbai.
Defending champions England have now lost three of their opening four games of their title defence and are in real danger of not making the semi-finals, as they slipped to a record defeat in one-day internationals.
They won the toss and elected to field, but had no answer to South Africa's power hitting, as their bowlers toiled in stiflingly hot and humid conditions.
Klaasen finished with 109 from 67 balls and put on 151 in 76 deliveries for the sixth wicket with all-rounder Marco Jansen (75 not out from 42 balls), the highest run-rate in a 150-run stand in the history of the men's World Cup.
England's reply never got going, as they slipped to 68/6, before a late rally from Mark Wood (43 not out) and Gus Atkinson (35) put on 70 for what proved to be the last wicket, with Reece Topley unable to bat.
"It was a fantastic all-round performance," said stand-in South Africa captain Aiden Markram. "We could not have asked for a bigger effort and to have the skills to top it off was very pleasing.
"It was a great way to bounce back [from defeat to the Netherlands] and to put a game like this together was superb from the guys."
South Africa were held in check in the opening overs, but when England seamer Topley went off with an injured finger, the pressure was released.
In the side for ill captain Temba Bavuma, Reeza Hendricks made an eyecatching 85 from 75 balls and put on 121 with Rassie van der Dussen (60 from 61 balls) for the second wicket.
Aiden Markram added 42, while David Miller managed only five, before Topley (3/88) removed both batters.
Klaasen and Jansen then went on the attack, as South Africa scored 143 in the last 10 overs of the innings to record the highest total ever against England at a World Cup.
The chase was always going to be a tall order, but England never looked like they would mount a serious challenge.
No.10 batter Mark Wood was topscorer in the innings and Ben Stokes, playing his first game of the tournament after a hip injury, could only manage five.
"It's incredibly disappointing," said England captain Jos Buttler. "We came here with high hopes to play our best cricket, and we were short of that and well beaten.
"I thought, if we could have restricted them to 340-350, probably on this pitch, it would have been a really good chase. They just got away from us at the end."
In the second tie of the day, Sri Lanka beat the Netherlands by five wickets with 10 balls to spare to become the final team to claim a hardfought victory at the World Cup, on the back of Sadeera Samarawickrama's unbeaten knock of 91.
The Netherlands won the toss and opted to bat first, but they had a poor start, after Sri Lanka fast bowlers Kasun Rajitha and Dilshan Madushanka ran through the top and middle order.
The European side were reeling at 91/6, when skipper Scott Edwards was sent back to the pavilion by Maheesh Theekshana, but Sybrand Engelbrecht (70) and Logan van Beek (59) rescued the Dutch side with a 130-run partnership.
The pair rotated strike and guided the team to a competitive total, but they were bundled out for 262 in the final over of their innings, as Rajitha and Madushanka finished with four wickets each.
In response, Sri Lankan opener Pathum Nissanka laid the foundation for their chase with a knock of 54 that included nine boundaries, but Aryan Dutt contained them with three wickets, dismissing Kusal Perera and Kusal Mendis cheaply.
Samarawickrama stood firm once again, with a patient 91 off 107 balls to add to his century against Pakistan, as the island nation wrapped up the contest in the 49th over.
Reuters
