England 171 for 4 (Buttler 66*, Roy 42) beat Sri Lanka 161 for 8 (Mathews 73*, Jordan 4-28) by 10 runs
Scorecard and ball-by-ball details
No country has ever successfully defended a World Twenty20 title so Sri Lanka are hardly alone in their mortification, but they crashed out in heartbreaking fashion in Delhi when they crumbled to a 10-run defeat against England in one of the most memorable games of the tournament.
Angelo Mathews is a Sri Lanka captain in challenging times, but his refusal to wilt reached heroic proportions. From the disarray of 15 for 4 in three overs, a target of 172 a world away, and with his first contribution to run out his batting partner, Lahiru Thirimanne, he summoned a muscular show of defiance, refusing to yield to the cruellest of hamstring injuries.
Mathews finished with 73 not out from 53 balls to show for his pain, his faith that he could turn the game only silenced by two excellent death overs from Chris Jordan and, ultimately, Ben Stokes, whose final onslaught of yorkers peppered the boots of an injured man and represented one of his most cool-headed overs in an England shirt.
So England qualified along with West Indies from Group 1, leaving India and Australia to fight out who will join New Zealand from Group 2. South Africa's chances of progressing to the last four were also ended by England's nerve-jangling victory, turning their final group game against Sri Lanka into a dead rubber.
Mathews began the resurrection by sharing a stand of 80 in 10 overs with Chamara Kapugedera, but by the time his half-century had slashed the requirement to 61 from five overs he was limping heavily with a tweaked hamstring that needed treatment from the physio.
It called for desperate measures. Sri Lanka's spurt had begun with 21 off an over from Adil Rashid. Now Sri Lanka demolished Moeen for 21 more. In those two overs, Mathews cleared the boundary four of the six occasions. England's four overs of spin cost 63 runs. They had anticipated rich pickings in Delhi, but it has not turned out that way.
Kapugedera skied Liam Plunkett to Stokes, falling over at deep midwicket, Thisara Perera flared briefly before perishing at mid-off. A match that had been nip and tuck throughout edged towards England when Root dived high to his left at mid-off to enable Jordan to silence Dasun Shanaka with Sri Lanka needing 17 from nine. Jordan also bowled Herath - finishing with 4 for 28, his best figures in T20 cricket.
That left Stokes to defend 15 from the last over - with Mathews on strike and rain beginning to fall. Mathews, grimacing, might have been run out second ball but Willey's throw was wide. He limped another two, Rashid getting a finger end on a chance at short fine leg. Stokes ended the uncertainty in emphatic fashion.
England will calculate that they produced their most complete display of the tournament when it was most needed. The No Fear mantra which has been a vital part of their development was tempered by an intelligent assessment of batting conditions and a surface that had been watered more heavily than against Afghanistan to hold it together gave England's pace quartet some heart. But thanks to Mathews they ran it mightily close.
If anything, England were slightly too cautious around midway, but, Jos Buttler-fuelled, they escaped to 171 for 4 - Buttler's unbeaten 66 from 37 balls giving them perhaps 10 more than they might have expected.
Sri Lanka's disarray against aggressive England new-ball bowling was spectacular. Tillakaratne Dilshan holed out to deep square leg from David Willey's third ball. Dinesh Chandimal flashed at Jordan's second ball and edged behind, Milinda Siriwardana stepped regally away to the leg side in Willey's next over but failed to clear extra cover and, next ball - Mathews' first - Sri Lanka's captain sent back Thirimanne, but Stokes hunted down his quarry from mid-off.
"We will have to be better at adapting," Eoin Morgan had warned when he lost the toss. England's batsmen had been headstrong against Afghanistan, recovering to make 142 for 7. This time the deliberation was evident. Jason Roy made 42 from 39 balls, an innings characterised by slicker foot movement against the spinners and a sharper mind than he has often exhibited. But only when Buttler took charge in the final overs could England envisage a winning total.
With five overs left, England were still only 99 for 3, but 72 spilled from the final quarter. Buttler switched focus from clever deflections to uninhibited cleaves. For Sri Lanka, there was no Lasith Malinga, death bowler extraordinaire, and it showed.
Mathews' resources were more evident at the top of the England innings than at the death. England's quiescence against spin made it logical for Mathews to attack them in this fashion from the outset.
Rangana Herath's pot belly is now so evident, at 38, that he might have been smuggling a Sri Lankan drum into the stadium, but he is a canny soul. He rarely opens the bowling, but he came on for the second over. His first ball gripped and almost bowled Alex Hales, his fourth had him lbw on the sweep, out without scoring.
With better luck, his legspin partner, Jeffrey Vandersay might have picked up Root with a googly in his first over - England's third. But Root and Roy held their nerve and by halfway England had clawed their way to 65 for 1. Vandersay removed both. Neither ball was among the best he bowled, but there is not a legspinner alive who has not taken a wicket with a long hop or two.
There was more for England to contend with, too, in the craft of Dushmantha Chameera whose mix of cutters at various paces also proved hard to come to terms with. When Herath was gravely picked off in his last over for six singles - England playing him with deference to the end - there were only five overs to change the tempo.
Buttler, promoted to No. 4, did just that. England were helped by Perera's first over, which went for 18. Mathews immediately pulled him from the attack, only for Shanaka - given the 18th over in his first bowl of the tournament - also to prove expensive, conceding the biggest six so far, a full-blooded 97m-blow over long-on by Buttler. Mathews had played a weak hand well, but by the time Perera found his yorkers in the last over, England had a total to defend.
David Hopps is a general editor at ESPNcricinfo @davidkhopps