England were great against Fiji on Sunday, but will somehow have to find even more this week against defending champions South Africa.

The level of the two quarter-finals played in Paris - New Zealand's win against Ireland and South Africa's win against France - was off the charts.

There were parts of England's game on Sunday that were at that intensity, but the consistency and longevity of those four nations to be able to play at that level for 80 minutes was utterly remarkable.

In a World Cup semi-final anything can happen and England are in with a shout as much as anyone else.

The gap between Steve Borthwick's side and the top teams in the competition has definitely narrowed as the tournament has gone on.

As history tells us, World Cup semi-finals affect individuals and teams in different ways.

South Africa have played three enormous Test matches - against France, Ireland and Scotland - whereas England have maybe just had one at that level - their quarter-final.

There is going to be some fatigue and fallout from that for South Africa and England are trending in the right direction.

They have got lots of momentum and lots of belief. They tested themselves against Fiji and they rose to the challenge.

In a World Cup semi-final you could be a referee's call, a bounce of the ball, a bit of ill discipline or a moment of brilliance away from victory or defeat. It's a very fine line.

'England have shown glimpses'

There has been plenty to take away from England's games against Argentina, Japan and Fiji.

They had some really impressive moments in those games. England's first try against Fiji was absolutely top drawer.

England had a great exit from their own 22, a great kick-chase with lots of pressure. They won a penalty, kicked to the corner, drove the line-out and Manu Tuilagi scored. It was just really clinical.

But we cannot get away from the fact that at this World Cup England have not yet faced opposition like South Africa or New Zealand - who play Argentina in the other semi-final.

In their quarter-finals, the Springboks and All Blacks played with such intensity and accuracy. The manner in which those teams take their opportunities means they score tries when there was never a try on.

England showed glimpses of that against Fiji. They were very much in control of the game but they had a lapse of concentration for 10 or 15 minutes that let Fiji level the scores late on.

That definitely has to be erased because in this case it could have cost them the game. A lack of concentration against South Africa definitely will cost them the game.

The last time England faced the Springboks in the World Cup was the 2019 final that they lost.

The one thing I am desperate for England to learn from that defeat four years ago is to rest. They do not need to lift a finger this week.

They can do all their analysis of South Africa and ideally come up with some really innovative plays, something the Springboks have not seen that will knock them on to the back foot.

But they will need every ounce of energy possible for this game. It should be a really enjoyable week where all they do is focus on what they need to do to beat South Africa.

'England using siege mentality'

A lot of the England players and coaches were very defensive post-match about what everybody else - some English fans or English media - think of them.

I get it if they want that as their motivation, but because the England camp do not give us any insight into how they are doing or what they are thinking, you have to comment on what you see from outside.

England were not in a good place going into this tournament. I did not think England were ever in doubt of not qualifying out of their group - that would have been a catastrophe.

But I do not think people thought the momentum they were building would be so steep, which is a credit to players, coaches and backroom staff.

England have been very active and sometimes over the top about how they want more from the fans.

They always get that. England fans love their England team, but they are still allowed to have an opinion on it.

England have obviously used that siege mentality and that is great. I just do not necessarily agree with the narrative.

I want to give them confidence that that is not necessarily how England fans think.

'England have to get selection right'

Many of the questions have been around team selection.

This week, there was discussion about Owen Farrell being selected over George Ford at fly-half and Marcus Smith starting in place of Freddie Steward at 15.

England have got to keep the bulk of their team now and certainly Farrell vindicated his selection. There will be a long selection meeting over full-back this week.

You just know South Africa are going to bring something different like they did against France. They exploited France with cross-field bombs and it is not by luck that they got so much change out of that.

It was a tactic that they practised and executed and they are the sorts of things that England should be taking the time now to get right.

As creative as Smith is, I am not totally sure it is going to be a game for that type of full-back.

You are going to need someone in the backfield who is absolutely rock-solid, like Steward.

A lot will depend on injuries, how people are feeling and what kind of gameplan England want to play.

The learnings will stare England in the face from four years ago, when they felt they got selection wrong.

England got it right to get the job done against Fiji. They have got to get it right for next week.

Matt Dawson was speaking to BBC Sport's Becky Grey.