|The young Welsh team have dealt with World Cup pressure better than many of their rivals [GALLO/GETTY]
France's ability to confound by switching attitudes is legendary in Rugby World Cups.
Exhibit A: Losing to Tonga on October 1.
Exhibit B: Eliminating England a week later.
So it's ironic that France look at their opposition in the semifinals on Saturday and wonder, who are these guys in Wales jerseys?
The French are used to facing Wales teams which have tended to be sloppy, tactically woeful, mentally fragile, and unfit.
"It has been bubbling for a couple of years and we have put in error-free performances that have got us the results"
Wales' James Hook
When they met in 2009, Wales were the defending Six Nations champ, poised to equal the tournament record of nine straight wins, but blew a 13-3 lead and lost 21-16. In 2010, Wales conceded two intercept tries, trailed 20-0 and eventually lost 26-20 in France's Grand Slam run.
This year, Wales had an outside chance of winning the Six Nations but lock Lionel Nallet charged down James Hook for his second try of the match, Hook also went to the sin-bin, and France won 28-9 to save themselves from their worst tournament in a decade. Defeat dropped Wales to fourth and handed England the title.
The hard-earned lessons for Wales were to cut down errors, kick with purpose, stay focused and get fitter.
The result is their first World Cup semifinal in 24 years.
"I think what's definitely been part of our problem against France in the past is that we've harmed ourselves,'' said Wales defence coach Shaun Edwards.
"So first and foremost we have to make sure that if France do get points against us, they have to earn them. If France are good enough to get points, well maybe so, but defensively we're determined to keep that to an absolute minimum."
Hook, who will start at flyhalf in place of the injured Rhys Priestland, was on the bench for the quarterfinal against Ireland but was impressed enough to describe their 22-10 win last weekend as a "pretty complete performance."
He was sure if the Welsh team can keep surfing the crest of their wave they can beat the French for only the second time in their last eight matchups.
"We have probably surprised ourselves a little bit at how we've performed here, but surprised other people a lot more," Hook said.
"It has been bubbling for a couple of years and we have put in error-free performances that have got us the results."
Only eight months ago, Wales were on an eight-match winless streak, their worst run in eight years. But two summer camps in the Polish Olympic training village of Spala have seen them rise to mythical status in the way the team bonded with daily dawn-to-dusk fitness work.
| The Welsh fans have enjoyed a campaign that few were expecting [GALLO/GETTY]
"We are obviously getting accolades for the way we have been playing, but once you get to knockout games you realise that these are the pressure games and when you want to be at your best," Edwards said.
"We feel the more pressure that is on us, the better we play."
About 50,000 have snapped up free tickets into Millennium Stadium to watch the match live on the big screens at sunrise.
Forwards coach Robyn McBryde said on Friday they were aware of the hype and embraced it. The relative youth of the squad meant it was "enjoying the moment," he said.
"We are not putting any limits on our potential."
France coach Marc Lievremont has done his best to up the pressure by praising Wales for their intelligence, team spirit and quality of rugby.
Nallet even said Wales were a different team, and he didn't mean the faces. But France has also been different, this week. The French spent the first month of the tournament riven by open dissent, largely caused by Lievremont's public criticism of players and the French media, and his renowned erratic selections.
Yet the team overcame two pool losses to squeak into the quarterfinals, where it outclassed England and justified the coach's unconventional methods.
This week, Lievremont left the team in a room on their own to watch and dissect the England game and address their own foibles among themselves. Nallet called the move refreshing.
More telling about the Tricolores was their reaction to the unexpected victory last Saturday on Eden Park.
Unlike when they shocked New Zealand in the 1999 semifinals and 2007 quarterfinals, the French didn't dance all over the field and in the stands and party long and hard.
"We know we are capable of beating Wales but the danger would be to look down on them"
France's Dimitri Szarzewski
France can back up big wins. They have won half of the Six Nations in the past decade, three of them by Grand Slams. Those facts reveal how underwhelming the team has been in the World Cup, topped by two losing appearances in the final, and how desperate they are to rectify that.
"We know we are capable of beating Wales but the danger would be to look down on them," hooker Dimitri Szarzewski said.
"We've got to respect them, be as focused as last week, and tell ourselves we are playing a semifinal to win it."
Saturday's first World Cup semifinal between France and Wales is likely to be an entertaining affair, but only the brave would bet on its outcome.