England's rollercoaster World Cup campaign continued as they lost by two wickets to co-hosts Bangladesh in Chittagong.
After a tie with India, losing to Ireland and beating South Africa, this latest defeat leaves England needing to overcome West Indies in their final Group B match next Thursday to qualify for the quarter-finals.
Batting first in the day-nighter, England toiled to 225 all out with just Jonathan Trott (67) and Eoin Morgan (63) managing notable contributions.
But after reducing Bangladesh to 169-8, England looked on course for the knockout stages before Shafiul Islam (24no) and Mahmudullah (21no) put on a match-winning stand of 58 for the ninth wicket.
It was a truly remarkable fightback from Bangladesh, who still need to overcome the Netherlands on Monday to keep their own hopes of making the knockout stages alive.
With heavy dew expected to make bowling and fielding difficult later on, Bangladesh captain Shakib Al Hasan inserted England, who named Matt Prior alongside captain Andrew Strauss at the top of the order.
Prior and Strauss put on 32 together, but their stand was broken in comical fashion when the England gloveman inexplicably left his ground following Abdur Razzak's leg-side wide, and Mushfiqur Rahim whipped off the bails.
Prior had made 15 at that point and the setback, just after Bangladesh had turned to spin at both ends, cut off England's early impetus.
Three overs later, Strauss (18) thought he saw an opportunity to attack off-spinner Naeem Islam off the back foot but instead edged to slip, where Junaid Siddique took a sharp and neat catch away to his right.
Warwickshire duo Trott and Ian Bell therefore had to start again, and the latter had not settled when he chipped a Mahmudullah off-break straight into the hands of midwicket.
Morgan, back in the side after a hernia injury cut Kevin Pietersen's campaign short, then launched a one-man fightback against the Bangladesh spinners, using his feet and chipping the ball over the infield on both sides of the wicket.
The only close calls came when Trott just made his ground for a sharp single on 25 and Morgan's edge flew narrowly wide of the wicketkeeper off Rubel Hossain on 28.
The Irishman's expert placement and timing brought him seven fours in a 60-ball 50 until both deserted him in one faulty sweep at Naeem to deep square-leg, where Imrul Kayes took a superb diving catch.
Trott had hit a solitary four in his 50 but seemed set on staying the course until he too holed out, off Shakib (2-49) at long-off.
His was one of two wickets in the final powerplay, during which England could muster only 28 runs to post a below-par final total, all out with two deliveries left unused.
Tamim Iqbal, the scourge of England attacks at home and abroad last year, made his intentions clear with a flurry of early boundaries as new-ball bowlers James Anderson (0-54) and Ajmal Shahzad (3-43) struggled to find a consistent line and length.
Tamim and Kayes took the score on to 52-0 before Tim Bresnan (1-35) came into the attack and snuck one through the former's defences after he had made a quickfire 38.
Then, after Anderson's direct hit ran out Junaid Siddique (12) and Shahzad produced a fine delivery to bowl Raqibul Hasan for a duck, England were favourites again.
However, Shakib and Kayes settled the ship with a calm stand of 81, moving the score along to 155-3 as a result.
They needed to take no risks to stabilise the chase - and after Imrul had moved past a 91-ball 50, the match seemed theirs to lose.
But Imrul gave England the opening they needed, needlessly calling for a second run and finding himself short of his ground after Shahzad's accurate throw.
With the pressure building, Shakib edged on to his stumps as he tried to sweep Swann and then Shahzad took over, producing his second near-unplayable delivery of the night to have Mushfiqur (6) very well caught by a diving Prior and then bowling Naeem (0).
Bresnan then claimed an oustanding outfield catch at deep extra-cover when Razzak tried to launch Swann, leaving Bangladesh on the brink of an early exit from the competition.
It seemed England would prevail with relative ease after all, until Mahmadullah and Shafiul capitalised on some substandard bowling - including 23 wides - to see their side home with six balls to spare.