Europe will take centre stage on Saturday as the World Cup enters a weekend of "win or go home" quarter-final action. In what is shaping up as the most unpredictable of all seven World Cups, Ireland and Wales get the knockout phase under way in Wellington while later Saturday the spotlight will be on fellow Six Nations rivals England and France. The southern hemisphere will have its chance to shine on Sunday when reigning champions South Africa face Australia in Wellington before hosts New Zealand play Argentina in Auckland in a match the All Blacks are widely expected to win. But that fixture appears the only one of the four that isn't too close to call. Ireland have never got to the semi-finals of any World Cup while you have to go back to 1987 for Wales's last appearance in the final four. This is a shot at glory for both sides but whereas it may be a last chance for an ageing Ireland "golden generation" led by inspirational captain Brian O'Driscoll, a Wales team where skipper Sam Warburton has only just turned 23 appear to have plenty of good days ahead of them. "The big thing for our group of lads is to maybe do something to separate ourselves from Irish teams that have gone before," said lock Donncha O'Callaghan. Meanwhile Wales wing Shane Williams, for whom a defeat could spell the end of his Test career, was excited by a team containing eight players aged 23 or under. "I think we have got stronger as the tournament has gone on. There are some great players coming through," said the 34-year-old Williams, Wales's record try-scorer with 55 in 83 Tests. No team has ever won the World Cup after losing one pool match let alone two as France did during group defeats by both New Zealand, and more surprisingly, Tonga last weekend. But England, who are bidding for a third straight World Cup final after winning the tournament in 2003 and losing in the climax to the Springboks four years ago, remain wary if confident in their own ability. "You are aware of what a French side is always capable of, you have that in the back of your mind -- but we know the quality of rugby we are capable of playing," said England captain Lewis Moody. Meanwhile France coach Marc Lievremont said he hoped the memory of France's grand slam winning victory over England last year would inspire his side as they tried to avoid a third successive World Cup exit at the hands of their old rivals. "The French have never really done that well against England in matches where there's a lot at stake, even though our squad managed to do it to win the grand slam in 2010." New Zealand are widely anticipated to be too strong for an Argentina team still searching for a first win over the All Blacks. But with star playmaker Dan Carter (groin) out of the tournament and influential captain Richie McCaw nursing a foot injury, New Zealand could yet suffer further damage against the traditionally physical Pumas, third at the 2007 World Cup in France. Colin Slade, Carter's stand-in, is a man under pressure, but he said: "It's an opportunity and one I've got to think positively about. I can't be in any way burdened by it -- I've got to be excited about it." Were Argentina to beat New Zealand, it would be one of the great all-time upsets and Pumas playmaker Felipe Contepomi admitted: "We have to try to do the perfect game... but we are up against the best team in the world." Australia have beaten South Africa, the only other team to have won the World Cup twice, five times in their last six Tests. But Springbok star Bryan Habana said: "Anything can happen in this competition. So yes, they've got the edge over us at the moment but in a knockout game that means nothing." New Zealand are in line to meet the winners of the Wallaby-Springbok clash and All Black coach Graham Henry said: "I hope they knock 25 bells out of each other, that would be great."