Wales seized their 20th Triple Crown in dramatic fashion after a hugely controversial ending to a gripping contest at Twickenham.
Scott Williams' brilliant steal, kick-ahead and try with five minutes remaining put Wales ahead for the first time after four penalties apiece from Owen Farrell and Leigh Halfpenny had the teams locked together at 12-12.
With time up, replacement Mike Brown put David Strettle over on the right but after several minutes of deliberation, television match official Iain Ramage ruled the winger had failed to ground the ball.
It means Wales now have the Grand Slam in their sights and handed England interim coach Stuart Lancaster his first defeat in charge.
Seven of England's starting XV had never played at Twickenham before but their performance belied that lack of international inexperience.
Official match stats
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(delivered by Accenture)
With Farrell pulling the strings, scrum-half Lee Dickson impressive on his first full cap and the defence rock solid, this was the best display of Lancaster's reign so far.
But Wales, despite losing Rhys Priestland to the sin-bin and struggling to replicate the fluid rugby of earlier in the month, did what all top teams do and found a way to win.
If it was a frantic finale, it was also a breathless start, Sam Warburton feeding Mike Phillips off the top of a line-out and the scrum-half sending George North away with a cute inside pass.
North seemed certain to score but was brought crashing down by a desperate full-length tap-tackle from Strettle. When the ball was recycled, Priestland put a kick just too far ahead of Alex Cuthbert.
Wales had three-quarters of the possession and almost as much territory in the first quarter, and although Strettle nearly picked off a poor Alun Wyn Jones pass for an intercept, the Welsh forwards then launched a series of rumbles deep in English territory.
Halfpenny missed a simple penalty chance after his pack made a mess of the English scrum, and when Dickson went on a dart after a tap-and-go, England finally made inroads
Manu Tuilagi hammered dents in the red defence and Farrell made it 3-0, only for Halfpenny to level things up after Chris Robshaw took a pass standing still and was smashed by Dan Lydiate.
Dickson's quick pass and Tuilagi's power were lifting England's backline. It took a desperate tackle from Warburton to deny England's outside centre but Farrell made it 6-3 when other defenders went offside.
Williams runs in match-winning try for Wales
Farrell then chipped over the onrushing Welsh defence and gathered in space only to be clattered backwards by the monstrous North, and Halfpenny landed his second penalty from distance for 6-6.
The game was being played at a ferocious pace, the intensity relentless and the atmosphere crackling. Farrell's third successful kick from the left touchline came after an England turnover in the Welsh 22 and meant Lancaster's young side led at the interval.
Within four minutes of the restart the game turned again. Mouritz Botha charged down Priestland's attempted clearance and looked odds-on to secure England's third charge-down try in three matches. And although Halfpenny scragged him, Priestland then went off-side and found himself sin-binned.
Farrell knocked over another nerveless penalty to extend the lead to six points and the choruses of "Swing Low" rippled around the packed stands.
Wales went through phases after phases but England's defence initially held firm against the 14 men until Jonathan Davies thumped into Farrell, Ken Owens barrelled on and Dylan Hartley went off his feet to allow Halfpenny to take his side back within a single score.
Errors began to creep in, turnovers slowing Welsh advances and Geoff Parling being bundled into touch on the left as a promising move crabbed sideways.
Lancaster threw Ben Youngs and Courtney Lawes into the fray. Priestland missed touch badly with a penalty and was then pinged for holding on when Ben Foden's clearing kick came back to him. Farrell, for once, could not take advantage, and England's lead remained just three as the minutes ticked away.
It was Farrell's last deed, cramp forcing him to hobble off and Toby Flood coming on in his place.
Strettle held up on line as Wales win
Welsh replacements Ryan Jones and Williams then worked a priceless opportunity for Warren Gatland's team to wrest back the initiative. Jones burst off a scrum, Williams sliced through the scrambling English rearguard and had North completely free out wide, only to take the ball needlessly into contact and get turned over to roars from the home crowd.
The pressure was making strong men weak. Matt Stevens kept his hands on the ball in a ruck despite repeated warnings from referee Steve Walsh and Halfpenny brought the scores level with just eight minutes left on the clock.
England came again. Lawes thundered down the left, Halfpenny scampered and Wales cleared. When Wales had possession just inside the England half another fumble forced Priestland to kick possession away.
Williams was not finished. Lawes crashed into three Welsh tacklers on halfway but the centre, on for an injured and ineffectual Jamie Roberts, ripped the ball from English hands, turned and span away.
With a kick through he was free, gathering a kind bounce to dive over the try-line as his team-mates celebrated in his wake. Halfpenny added the extras and the Triple Crown was within their grasp.
England needed a converted try to save the game. They went right, then left, and with time up a long mis-pass found Strettle sprinting for the right-hand corner.
Halfpenny and Davies threw themselves at man and ball with North also playing a hand; the crowd celebrated and it went to the television match official for a heart-stopping age until the fateful decision came: no try.
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