This is where the fun really starts. Ireland have known they would be facing South Africa in the third game of this World Cup for two and a half years and now that it's finally upon us, the excitement is really kicking in.

But Saturday night in Paris is where this side's World Cup journey really kicks into high gear.

It's the top two teams in the world. It's the Grand Slam winners against the reigning world champions, under the lights on the biggest stage France has to offer.

For rugby fans, it really doesn't get any better than this.

'South Africa got my blood racing'

South Africa's team announcement on Tuesday really got my blood racing. By naming seven forwards on the bench, they have set out their stall. We know exactly the brand of rugby they are going to try to play in Paris - it's nothing we haven't seen from them before.

But Ireland won't be overawed by the whole thing. After all, they beat the Springboks in Dublin last year. On that occasion, Ireland's pack fronted up brilliantly to South Africa in a way few teams would be capable of.

This time, South Africa will want their so-called 'Bomb Squad' to come on and tire out the Irish pack. It worked against New Zealand at Twickenham last month, but Ireland will be ready.

It is surprising, however, that Willie le Roux has not been picked for South Africa. In that Dublin match, he made a huge difference when he came on in the second half. Ireland were 10 points ahead at that stage, but Le Roux played a key role in bringing the Boks back into the game.

Jacques Nienaber not picking him is a big gamble in my opinion - his absence could be keenly felt.

I was shocked by Andy Farrell's team selection for the Tonga match, but there were fewer shocks this time around. Jamison Gibson-Park returns to scrum-half and it's no surprise because he is key to Ireland's attacking tempo.

I'm not surprised Farrell has stuck with the tried-and-tested model of naming five forwards on the bench. That's what has worked for Ireland, so why change it now?

And there has been so much focus on the South African forwards on the bench, but Ireland have a fair amount of size and power in reserve, too.

Robbie Henshaw may be a centre but he is almost like another forward, while Iain Henderson and Ryan Baird will add a lot of physicality to the Irish cause in the second half.

Johnny Sexton again will be crucial to Ireland's plan. He's looked superb so far in this tournament and, while the task of moving the big South African pack around is a daunting one, I've no doubt he will be up for the challenge.

On the other hand, I just don't see Manie Libbok as a fly-half of Sexton's level. That could be crucial. The game management between two elite teams like this can have a massive impact and, for me, Sexton certainly has the edge in that respect.

Not having Handre Pollard, who was brilliant in the 2019 World Cup, may be a big loss from a South Africa perspective and the same can be said at hooker with Malcolm Marx out injured.

In contrast, having Dan Sheehan back fit enough for a place on the bench is huge for Ireland. Leaving out a player like Rob Herring shows the strength in depth available to Farrell in that position.

'Not make-or-break'

This is the biggest show in town this week, but it's important to remember that it won't be make-or-break for Ireland, or South Africa for that matter.

It will, however, be a revealing window into just how ready this Irish side are for a crack at the World Cup.

They have played some unbelievable rugby recently and if they keep the tempo up, they will have a great chance of delivering a famous win in front of a massive group of Irish supporters at the Stade de France.

The biggest incentive is taking the pressure off the Scotland match. In my mind, Ireland facing France or New Zealand in the quarter-finals is much of a muchness. A lot of people have said Ireland want to get New Zealand.

Yes, the All Blacks have lost to South Africa and France recently, but we're getting ahead of ourselves if we're painting New Zealand as the 'weaker team'. They are still New Zealand after all.

France showed last week they're not perfect and still think they're there for the taking. As long as Ireland get through South Africa injury-free, and with a performance they can be proud of, they'll still be on the right track.

This is not do-or-die territory just yet, but it will be the game everyone will be watching. Whether the players want to admit it or not, the pressure is on and the glare of the spotlight has never been so bright.

For Ireland, it's time to go out there and show the world why they're the best team around.

Tommy Bowe was speaking to BBC Sport NI's Matt Gault