James Lawton: Silent assassin Faletau gives Wales belief they can land the killer blow

Should Wales this morning find the highest ground of their rugby history and reach the final of the World Cup, if they continue to threaten brilliantly the game's old balance of power, let no one place too many layers of mystery on a stunning achievement.

If it happens it will, after all, be as unambiguous as the cleanest punch thrown at an under-prepared opponent.

It will have the moral authority of an argument shorn of all pretension and self-indulgence.

It will be stripped of the smallest intimation of brainless swagger, and if there is an implied criticism of less successful challengers assembled beyond the north, east and south of the Principality it should probably rest where it may for the time being.

No, it hasn't happened yet and the beauty of the Welsh, their attitude of mind and spirit, is that they have been the first to say so.

We were reminded of this yesterday when they came to the scene of their semi-final battle with France, the Eden Park fortress so central to the lore of the All Blacks, and continued to look, to say the least of it, a million dollars.

The young dragons were resplendent once more in the midday sunshine – and this despite the fact they scarcely broke the silence of the great stadium.

They worked with an easy rhythm, and you understood all over again the pleasure Kiwi coach Warren Gatland takes in the qualities of key players like 23-year-old captain and flanker Sam Warburton, and his brilliantly mature allies, the crashing centre Jamie Roberts (24) and the emerging full-back Leigh Halfpenny, who went through a 50-50 foot operation shortly before boarding the plane, and is all of 22.

Gatland, once again, looked like a generously proportioned Persian cat when he noted that another work session had gone by without a single Welshman dropping the ball.

Yet there is, it has to be allowed, one element of mystery which does lie at the very heart of this extraordinary Welsh campaign. It concerns precisely what is going on in the head of the player who in many ways has made the most remarkable contribution of all. On the field 20-year-old Tangaki Taulupe "Toby" Faletau is one of the most eloquent rugby players alive.

He is the wonder of his team-mates, impervious to hurt, relentless in his urge to take the game to the opposition, to skewer them at the heart of the breakdown. He also raised the Welsh banner with a try that helped push the reigning world champions South Africa almost to the point of defeat in the opening game.

Today Faletau takes on one of the icons of world rugby, France's relentless No 8 Imanol Harinordoquy, a challenge which, astonishingly when you consider his age and the fact that this will be just his ninth international game, is considered not much more than a routine assignment by Gatland.

Yesterday Faletau was asked if the prospect of confronting such a great man had given him a moment's cause for reflection, perhaps even a flicker of intimidation. It was not that the question was despised, rather it was greeted as merely odd. After a huge pause, Faletau said: "All the players you face at this level are good. No, I don't feel any differently about tomorrow."

If he is a coach's delight, he is a publicist's nightmare. When Wales submitted to the ferociously low temperature (-120C) of the cryotherapy chamber of the Polish Olympic Sports Centre – an ordeal which has contributed to the belief that this is the fittest-ever Welsh team – he was invited to explain how it was. After some consideration, he announced: "It was very cold."

Again he was undemonstrative yesterday when he reported that his parents had just flown in. It was a journey provoked by the quarter-final victory over Ireland, another match in which Faletau produced a performance which was as controlled as it was dynamic. No, he said, he didn't have any emotional scenes to report. His father, Kuli, just said: "Stay as you are."

No doubt Gatland would echo the request. Kuli played for Tonga in the 1999 World Cup, moving to Wales shortly before the tournament, when Toby was a seven-year-old and had already announced to his old prop father that maybe he had a wider potential for the game he had made his life. The old man played for Ebbw Vale, then Pontypool; the boy won a rugby scholarship to Filton College, Bristol.

Yesterday they had a brief war council – it was brief, Toby suggested, because there weren't too many issues to resolve. The French had shown impressive form against England, especially in the first half and had some talented players, but Wales could counter anything they had to offer. Toby went back to his room and listened to music – and waited for the action. He does it, his coach and team-mates say, with what might be described as relentless serenity.

Gatland has been widely praised for his willingness to let youth fly but he says that sending in Faletau, even against a warrior of Harinordoquy's dimension, was one of the less demanding decisions. The kid first played for Wales against the Barbarians earlier this year. Now he is one of the foundations of the team, just eight caps into his pursuit of glory.

It is his sheer rugby intelligence that most excites the coach. "He can deal with anything that comes his way," says Gatland. "It is as though he has got his own radar equipment. He sees things happening quicker than anyone else around. I wouldn't worry about sending him in with anyone – and that's why he is playing against France.

"Yes, it's a huge game but we are also talking about a great talent."

Warburton offers his endorsement, which is as startling in its enthusiasm as its source. The Welsh captain is widely described as the sensation of the tournament, a player of both absolute conviction and consistently impressive performance. Yet when he speaks of Faletau he widens out the pool of awe in which he has dominated so powerfully.

"The word I use most for Toby is 'unbelievable'," says the captain. "He starts every game and he wakes up the next day and he is not even aching. He is so professional, playing alongside him is an amazing experience. He is a chilled-out guy who you just want to be around when you go on the field.

"When I was 20 I was in no shape to play No 8 in a World Cup semi-final. For someone so young he's got the most incredible stuff. Sometimes I think of what he is going to be like when he gets to be 25. He's going to be a hell of a handful."

There is a touch of mystique here – and it is one hardly discouraged by former Welsh hooker – and the strongest man in Wales – Rob McBryde, who is now a coach of forwards. "Along the way some people thought we were too young, too green, but the boys have been incredibly mature – and relaxed about what they've had to do," says McBryde. "I've said before that experience can work for you but then it can go against you when the same old faces are looking for the same old answers."

This was probably a veiled reference to the overthrowing of the Irish in the quarter-final, when a much honoured old guard found themselves pummelled and broken by the force of young men like Warburton and his back-row partners Dan Lydiate and Faletau, who never aches.

Today they will seek to inflict their hurtful ways on the brilliant but ageing trio of Harinordoquy, captain Thierry Dusautoir and the clinical Julien Bonnaire. It could well be the breaking ground, the one to define the new range of the Welsh game that not so long ago was thought to be in irreparable decline.

Not, though, yesterday in the great old stadium where Toby Faletau mostly kept a silence that will never be mistaken for that of a lamb.

World Cup Fixtures

Semi-finals

Today: Wales v France

Auckland, 9am, ITV 1

Tomorrow: Australia v New Zealand

Auckland, 9am, ITV 1

Third place play-off

21 October: Auckland, 8.30am, ITV 1

Final 23 October: Auckland, 9am, ITV 1