Williams gets Wales off hook baited by Farrell

England 12 Wales 19: Replacement back helps favourites take their 20th Triple Crown after an almighty battle with a young England side inspired by a strikingly mature 20-year-old fly-half

Scott Williams flies in to score the only try of the match in Wales's victory at Twickenham (Getty Images)

What had looked for a while to be a victorious anointing of a new England hero turned into a Triple Crown dance by the ecstatic Welsh. An hour's worth of cajoling and cool goal-kicking by the home fly-half, Owen Farrell, had the home side smelling red roses. But though they, like Wales, came in with two wins out of two in the Six Nations, it was Sam Warburton's side who left with the Grand Slam still in their sights.

Asked on the field after the final whistle to remind himself and the crowd that Wales's only previous win here in 24 years had been during the Grand Slam of 2008, the visitors' captain was as cool and considered as his battering tackles and less predictable prowess in the line-out had been brutal and brilliant.

"I'm not going to jinx myself, I'm not going to say it," Warburton said. "We've got Italy in two weeks' time and we won't look any further than that." To complete the Grand Slam the Welsh need to beat Italy and France on successive Saturdays at the Millennium Stadium.

Today is a big one for Warburton, a Cardiff Blue whose heart will be pounding over his team, Tottenham Hotspur, playing at Arsenal in the Premier League, not Cardiff City, who will attempt to round off a remarkable sporting weekend for the Welsh in the Carling Cup final against Liverpool at Wembley.

England's interim head coach, Stuart Lancaster, was unable to enhance his claims to a permanent job with a win to follow those in Italy and Scotland with which his team began the Championship. But there was plenty to build on; even to get excited about.

Wales were dangerous early when George North, one of their half-dozen back-line giants, broke through from a line-out. But immensity comes in many forms – self-belief being one. As the first half wore on Farrell, 20 years of age and nine months on from a 17-point effort in Saracens' Premiership final victory over Leicester, showed his bottle.

There were two chip and chases – one in centre-field neatly reclaimed, the other, in Wales's 22, probably ill- conceived. What they achieved, though, was to dispel the idea that England would aim to tackle Wales all afternoon and kick the corners when in possession. Not that running repeatedly into a white wall was any use to Wales, either.

After Leigh Halfpenny's 19th-minute penalty miss Farrell and Halfpenny exchanged kicks up to half-time, for England to lead 9-6. Warburton twice spared his side worse punishment: a tackle on Manu Tuilagi and a pluck from the air when Chris Ashton went raiding. The changes made by Lancaster were working: Geoff Parling was winning his line-outs, Ben Morgan and Lee Dickson were marauding and Tuilagi at centre was all boldness and brashness. The tactics looked good too, as Farrell bombed North with restarts, guessing the tall Scarletwould run or be bottled up.

But the boy who would be king could not rule over his own anatomy. After 9-6 became 12-9 and Wales lost Rhys Priestland to the sin-bin for offside under his posts, there was a good position for Ben Foden and a great one for Scott Williams – each butchered, with a soft kick and by holding on, not passing. Meantime, Farrell winced and cramped up. He had to stretch both legs elaborately before taking a testing kick from the 10-metre line that drifted wide. Toby Flood came on soon after.

So we had the return of the dropped – Ben Youngs on for Dickson, Ryan Jones for Alun Wyn Jones – and the crocked, with Flood. Wales's Jamie Roberts had gone lame, to be replaced at the interval by Williams.

England began to unravel. Chris Robshaw tipped Warburton over in a line-out. Then Tom Croft was pinged for not rolling away and Halfpenny levelled at 12-12 after 71 minutes. When within four minutes Courtney Lawes was tackled by Warburton and allowed Williams to rip the ball and run in a joyous try with a kick and chase, Halfpenny converting, Wales homed in on a 20th Triple Crown. It was their first to be completed at Twickenham, largely because in the old days of brown balls and black-and-white newsreel this used to be the international season's opener.

Now the final act was the television match official taking numerous looks at slow-motion replays, after England worked a position in the last seconds. Wales conceded two penalties at the breakdown, Flood went to touch, Parling caught a line-out and Wales appeared to drive in illegally. With a penalty advantage that never came back, England attacked to the right through Flood's long pass to Mike Brown and on to Strettle. Halfpenny hit his thighs, Jonathan Davies came in high and North did the rest as the ball was never, quite, pressed down over the line by Strettle’s right hand.

After three minutes or so of deliberation Flood was all teed up with nothing to kick as Iain Ramage told Steve Walsh, the referee, "no". Cue Welsh celebrations, justified in their very rare billing as favourites here. Just.

England B Foden; C Ashton (both Northampton), M Tuilagi (Leicester), B Barritt, D Strettle; O Farrell (all Saracens), L Dickson (Northampton); A Corbisiero (London Irish), D Hartley (Northampton), D Cole (Leicester), M Botha (Saracens), G Parling, T Croft (Leicester), B Morgan (Scarlets), C Robshaw (Harlequins, capt). Replacements B Youngs (Leicester) for Dickson, 60; C Lawes (Northampton) for Botha, 60; T Flood (Leicester) for Farrell, 66; M Stevens (Saracens) for Corbisiero, 66; R Webber (Wasps) for Hartley, 72; P Dowson (Northampton) for Morgan, 72; M Brown (Harlequins) for Foden, 77.

Wales L Halfpenny; A Cuthbert (both Cardiff Blues), J Davies (Scarlets), J Roberts (Blues), G North; R Priestland (both Scarlets), M Phillips (Bayonne); G Jenkins (Blues), K Owens (Scarlets), A Jones, AW Jones, I Evans (all Ospreys), D Lydiate, T Faletau (both Newport Gwent Dragons), S Warburton (Blues, capt). Replacements S Williams (Scarlets) for Roberts, 40; R Jones (Ospreys) for A W Jones, 54.

Referee S Walsh (Australia).

England

Pens: Farrell 4

Wales

Try: Williams

Con: Halfpenny

Pens: Halfpenny 4