Hong Kong claimed a famous two-wicket win over Bangladesh but it wasn't enough to deny the host nation a place in the Super 10 stage.
The formbook was completely turned on its head in Chittagong as Hong Kong, who were already eliminated from the competition, stunned Bangladesh, who were seeking a third win on the spin.
The home supporters were left shellshocked after some bizarre batting from the Tigers saw them slump to 108 all out in just 16.3 overs.
Hong Kong made hard work of the chase but eventually crossed the line with two balls to spare thanks to Munir Dar's vital knock of 36 down the order.
Despite the shock defeat Bangladesh have secured their place in Group 2 of the Super 10s alongside Australia, India, West Indies and Pakistan by virtue of a better net run-rate than Nepal.
Hong Kong's triumph, their first over Bangladesh, is only the fourth time an associate member has beaten a full member in the ICC World Twenty20.
It could have been even worse for Bangladesh had Hong Kong reached their target in 13.1 overs or less, an outcome which would have resulted in their elimination at the expense of Nepal, who had stunned Afghanistan earlier in the day.
But their bowlers, in particular Shakib Al-Hasan (3-9), got them out of jail and set up a nervy finish.
Shakib accounted for Hong Kong's top three, but only after opener Irfan Ahmed, who came into the match on the back of two golden ducks, crashed 34 off 28 balls to get the minnows on their way.
Strangled by spin, the run-chase looked beyond Hong Kong when they collapsed to 83-6, however 42-year-old Dar put them on the brink before No 9 batsman Hassed Amjad sealed a famous win with a six off Abdur Razzaq.
Bangladesh had earlier pressed the self-destruct button with the bat to gift Hong Kong the chance of victory.
Tamin Iqbal and Sabir Rahmann both fell in the opening over to seamer Tanwir Afzal but Anamal Haque and Shakib restored order with a 48-run stand for the third wicket.
The collapse thereafter was spectacular, Bangladesh losing 7-23 to be bowled out with 21 balls to spare.
Slow left-armer Nadeem Ahmed (4-21) accounted for four of those wickets to scoop the man of the match award and and fellow spinner Nizakat Khan (3-19) picked up three.