Hosts South Africa were left in a spin in their International Cricket Council (ICC) Under-19 World Cup Super League quarter-final, soundly beaten by Bangladesh.
It was a bad day all round for the South Africans, having won the toss at JB Marks Oval, Potchefstroom, and inserted their opponents.
Openers Mohammad Parvez Hossain and Tanzid Hasan put on a solid 60 for the first wicket, while a mini-blip saw them reduced to 73-2.
However, Hasan hung around to score a rock-solid 80, before a half-century from Towhid Hridoy and an unbeaten 74 from Shahadat Hossain led Bangladesh to 261-5 from their 50 overs.
A good start was imperative for South Africa, and at 34-0 they looked in good shape, before spin bowler Rakibul Hasan really found his rhythm.
He had opener Jonathan Bird caught by Shamim Hossain for 35 and the crucial wicket of captain Bryce Parsons for just seven.
Luke Beaufort put up some stiff resistance, but he was out for 60 in a total of 157 all out in 42.3 overs, 105 runs short of the target.
Hasan finished with outstanding figures of 5 for 19 off 9.3 overs.
Bangladesh now face New Zealand in the Super League semi-finals on February 6, while South Africa play West Indies in the Super League playoff semi-finals.
In today's other games, rain brought a premature end to the Plate semi-final between Scotland and Sri Lanka, who posted a substantial 277-6.
Half-centuries for opener Navod Paranavithana, captain Nipun Dananjaya and Ahan Wickramasinghe did most of the damage.
Scotland started well, putting on 35 for the opening wicket, but the Sri Lankan bowling attack made regular inroads.
When the rain forced the players off the pitch, Scotland were 149-8 off 40 overs, still 128 runs adrift.
The Duckworth-Lewis method gave Sri Lanka a revised 97-run victory, sending them through to the finals of the Plate championship.
In the Plate playoff semi-finals, United Arab Emirates easily chased down the target of 146 set by Nigeria, scoring 146-3 in 29.2 overs.
Canada were also way too strong for Japan, with Nicholas Manohar's 101 inspiring them to a massive 300-7 - Japan were bowled out for 118.
Tomorrow sees the Plate semi-final between England and Zimbabwe, and the concluding Super League quarter-final between Afghanistan and Pakistan.