The safety net is gone.

The stakes and the standards have just risen to another level.

So, who will prevail?

Saturday, 14 October

Wales v Argentina (16:00 BST)

Wales' progress has come at a price.

The loss of number eight Taulupe Faletau against Georgia has been compounded by Gareth Anscombe's injury, which may yet rule him out. They are both key players.

But Warren Gatland and his side have a happy habit of stepping up when they need to. They have a fantastic pedigree of raising their level in the latter stages of this competition.

Gatland will be reminding them of the opportunity in front of them. They have a very winnable game for a place in a World Cup semi-final.

Fly-half Sam Costelow is inexperienced. He was making only his third start when he stepped in for Anscombe against Georgia. But I thought he played intelligently and kicked his goals well.

Argentina looked better against Japan in their final Pool D game, but, up until that point, I thought they had lacked cohesion and rhythm.

That game, coming a day later than Wales' game against Georgia, won't have helped them overall. It was a really intense one, with lots of running, open rugby in hot conditions in Nantes.

I think it will be a really tough ask for them to turn over Wales.

Ireland v New Zealand (20:00 BST)

New Zealand are a very dangerous beast. They have recovered from their opening-day defeat by France by scoring a total of 36 tries in their wins over Namibia, Uruguay and Italy and showing their free-flowing, intelligent rugby.

But in a top-end Test match, against an Ireland side who have not put a foot wrong in the tournament, you need more. You need to be able to back up those moments of genius with relentless physicality and faultless consistency and I just don't think the All Blacks have that gear in them.

Scotland are a very good team. They came into Saturday night's match motivated. They had talked up the possibility of beating Ireland. But, they couldn't lay a glove on them. Ireland's dominance started in the front row with Andrew Porter, Dan Sheehan and Tadhg Furlong, but their whole forward pack was massive. Captain Peter O'Mahony was a totem for them, as he is game after game. Garry Ringrose in the centres was imperious as well.

And Ireland have a 16th man, with the fans at the Stade de France. They beat South Africa there a fortnight ago, they beat Scotland there on Saturday and they will play New Zealand there at the weekend. Paris has become a home from home with thousands of supporters in the stands and the streets. The team feed off the fans, the fans feed off the team and the connection feels really personal between the two.

Ireland have been too good for too long and have too much momentum for the All Blacks.

Sunday, 15 October

England v Fiji (16:00 BST)

This is a mighty close call.

For large parts of the pool stages, Fiji have played better than England. They closed out victory over Australia well and, on the opening weekend, were potentially a Semi Radradra handling error away from beating Wales.

The defeat by Portugal in their final Pool C match was less impressive, although, by then, I think they were already looking ahead to England and the last eight.

Fiji go into that quarter-final buoyed by a landmark victory at Twickenham less than two months ago. That result and England's laboured win over Samoa in their own final pool-stage game showed how Steve Borthwick's side struggles against the ball movement and power typical of the Pacific Islanders' game.

England have to go to their strengths and make inroads through their set-piece before they spin the ball any wider.

To do that you need George Ford running the show from fly-half and I don't think Owen Farrell's presence outside him helps. They certainly didn't seem to function well together against Samoa, after some promising performances against Argentina and Japan in Farrell's absence.

England have greater experience of the Rugby World Cup knockout stages with veterans of the Japan 2019 campaign throughout the team, but let's not over-state the difference.

Fiji have Levani Botia who has played in the last three Champions Cup finals. They have Josua Tuisova who has played in an Olympic final. Half of their squad play their rugby with big European clubs and are used to week-in week-out high-quality rugby. The other half now get exposed to some of the best rugby in the southern hemisphere with the Fijian Drua's participation in Super Rugby.

They are tactically astute and disciplined in defence, while retaining that attacking edge, even if some of the old inconsistencies remain.

I think England's forward power will just about see them home, but they have to be so much clearer and more clinical compared to the Samoa game.

France v South Africa (20:00 BST)

The hosts against the holders - I think this is the toughest one to call of all the last-eight games.

One thing in France's favour is the support of the home nation. We have sometimes wondered if the occasion and expectation might prove too much for them, but head coach Fabien Galthie, team manager Raphael Ibanez and defence coach Shaun Edwards seem to be able to manage them through the pressure.

It is a brains trust of coaches who have been on the biggest stages and biggest games and know how to manage the build-up.

We saw it on the opening night when they beat New Zealand at the Stade de France and we saw it when they closed out the Grand Slam last year against England on the same stage.

We also saw it in Marseille last year when they beat South Africa 30-26 in a superb game. France lost Antoine Dupont that day to a red card and still won.

Dupont is still coming back from a facial fracture sustained against Namibia and may not be quite ready for this game. Any team is going to miss the world's best player, but Maxime Lucu, who has stood in at nine, has been an excellent understudy.

South Africa have the tools to beat France. Their defence comes up so fast and they tackle so hard that they can defend the gain-line and slow down France's supply of ball.

But France have threats across their team and the intelligence and composure to find them and depose the defending champions.

Matt Dawson was speaking with BBC Sport's Mike Henson