Record-breaking Bangladesh condemned South Africa to a second Cricket World Cup defeat in four days, subduing the lackustre Proteas by 21 runs at The Oval.
Talisman all-rounder Shakib Al Hasan became the fastest man to 250 wickets and 5,000 One Day International runs in his 199th match, with a vital one for 50 with the ball and 75 with the bat.
Bangladesh notched their highest-ever ODI score of 330 for six, to add another World Cup scalp of South Africa to their famous win of 2007.
Mushfiqur Rahim fired 78 to share a 142-run third wicket stand with Shakib, who leaked just two fours in his 10 overs with the ball.
Mustafizur Rahman plundered three for 67, with Mohammad Saifuddin taking two for 57 in a comprehensive victory to expose serious shortcomings in the Proteas ranks.
South Africa simply had no answers, unable to pull off what would have proved a record World Cup run chase – and were left to leave south London licking their wounds and counting a rising injury tally.
Lungi Ngidi's frustrations boiled over when he took a needless coconut-shy pitch at the stumps while standing on the square with Tamim Iqbal obviously in ground and forced to block the ball.
The 23-year-old paceman's day quickly worsened as he hobbled out with a hamstring injury having bowled just four fruitless overs.
Now Ngidi joins the concussed Hashim Amla and shoulder injury-carrying Dale Steyn as doubts for Wednesday's pivotal clash with India in Southampton.
South Africa could ill afford to add another loss to Thursday's 104-run defeat to hosts England, but Bangladesh squeezed Faf Du Plessis' men from start to finish.
Bangladesh cared not for South Africa's troubles however, powering to victory to kick-start their tournament in style and tee up an intriguing clash with New Zealand back at The Oval on Wednesday.
Bangladesh just managed to top their previous ODI record of 329 for six, that came against Pakistan in 2015. Had Imran Tahir not bagged a smart two-wicket brace South Africa's ignominy would have deepened still further.
The Proteas' decision to bowl backfired spectacularly as Bangladesh reached 190 for two after 30 overs, with Shakib and Mushfiqur comfortable in their century stand.
Tahir bagged two wickets in 10 balls for just seven runs to hand South Africa a chance, but Mahmudullah and Mossadek Hussain threw the bat at the death to inch Bangladesh to that record score.
Quinton De Kock's mix-up run out summed up South Africa's day, the wicketkeeper batsman departing for 23 after Aiden Markram rejected a run.
Shakib clean bowled Markram, then even doughty skipper Du Plessis threw his wicket away on 62.
The captain had looked in total control until drawn into a false shot by Mehidy's smart bowling and captain Mashrafe Mortaza bringing up long off to mid off as a tempter.
Rassie Van Der Dussen and JP Duminy both reached the 40s, but neither could kick on as Bangladesh continued to turn the screw.
The Proteas ended on 309 for eight from their full allocation; some way shy and doubtless prompting a sizeable internal inquest.
