The Nations Championship, which is already three rounds old after the summer window, gives fans a chance to see the best sides in the world compete against each other in a meaningful competition just 12 months out from the Rugby World Cup.
The top four sides all earned big wins as the competition returned for Round 4, while some sides will be doing some soul-searching this week.
The Springboks remain the side to beat, but who else could rival them 'Down Under' next year? And who has cause for concern?
- Nations Championship huddle: Pollock stars, Erasmus unsatisfied, Australia in crisis?
1. South Africa flex their muscle
Previous ranking: 1 
It was always going to be a fairly routine start for South Africa against Italy and even without some key players, they made it look easy. Italy were, to be fair, without the likes of Tommaso Menoncello, Michele Lamaro and Sebastian Negri, but the Springboks ruthlessly exposed the gulf in class between the two, scoring 38 points within half an hour. In truth, the game was over after 15 minutes when they took a 15-0 lead.
France await the Boks on Friday in what will be a much more competitive and fascinating contest.
2. New Zealand produce second-half clinic
Previous ranking: 2
In what is a crucial tour for Dave Rennie as he nears the end of his first season as coach, the All Blacks showed their class after a traumatic week following the sudden death of their head of security, Logan Cadwallader.
Scotland stayed in the fight in the first half at Murrayfield but thanks to a barnstorming effort from the back row as well as a back line that hardly missed a beat, New Zealand won at a canter.
3. Antoine Dupont shines for France
Previous ranking: 3
Fiji were never going to be a threat to France, but it gave Les Bleus a chance to shake off any rust before the big one against the Springboks this Friday. On paper, if any northern side can go toe-to-toe with the two-time defending world champions, it's Six Nations title holders France. And, when Antoine Dupont is at his best, they're capable of beating anyone on their day.
4. Ireland dismantle Argentina
Previous ranking: 4
Ireland looked like a side who, after a period of change and evolution, were very sure of themselves. Hugo Keenan was sensational with a hat trick, while fan favourite Mack Hansen was a welcome return.
At a time when some senior players might see their roles changed, the newer faces stepped up again. Robert Baloucoune is a constant threat and powerful presence on the wing and while Jamison Gibson-Park remains the premier scrum-half, Craig Casey made his mark in the starting XV.
5. England win it for Borthwick
Previous ranking: 6
England harnessed a siege mentality ahead of their return to Twickenham amid reports of player unrest and tension with coach Steve Borthwick. Captain Maro Itoje and Jamie George insisted prior to the clash with Australia that they were behind the coach and they ultimately proved it with a commanding 45-22 victory.
Itoje doubled down on his backing of Borthwick post-match which gave England an air of confidence that has been missing a bit this year.
Eddie Jones returns this week with Japan in what is always a fun occasion and it gives England a chance to build more momentum ahead of a huge clash with New Zealand.
6. Scotland crumble at home
Previous ranking: 5
Frustrating, disappointing, déjà vu ... All of these fit for Scotland this week.
A near fully-fit side would have been confident they could match the All Blacks and perhaps be the first Scotland side to beat New Zealand. The reality is they didn't get close. Penalty after penalty gave New Zealand all the momentum and Scotland find themselves again having to respond after a hefty defeat.
7. Wales earn gritty win
Previous ranking: 10
They would have wanted the win to be slightly more comfortable, but the 28-21 win over Japan will be hugely valuable for Wales. To grind out a victory against a decent Eddie Jones-coached side will do wonders for the Welsh confidence.
It's also simply a win ... an achievement that has been few and far between for Wales since the 2023 World Cup.
8. Australia make desperately poor start
Previous ranking: 7
Australia were bitterly disappointing against England. They arrived at Twickenham after a decent season but eager to respond after back-to-back defeats to New Zealand. What they produced was far from their potential or what was expected of them.
Their attack never got going and the errors mounted quickly. The two sides could meet again in next year's World Cup quarterfinals, something that won't have gone unnoticed by Les Kiss and his players. It's a reminder of how much work they have to do before hosting rugby's showpiece.
9. Japan show fight in Cardiff
Previous ranking: 11
Japan might feel like they should have got more from the game against Wales but it was an admirable effort. They were always in the game and asked questions of their opponents constantly. England will be another big step up next week but with Eddie Jones at the helm, Japan will always have something up their sleeve.
10. Argentina way off the pace
Previous ranking: 8
This year is turning into a bit of a write-off for Argentina. A side that has, in recent years, troubled the best sides in the game just haven't been able to produce 80 minutes of good rugby consistently enough. The game against Ireland was over by half time and Argentina's heads seemed to drop a bit. They struggled to ask any serious questions of their opponents and looked devoid of ideas at times.
11. Italy falter amid injuries
Previous ranking: 9
There are a couple of caveats for Italy. The first being they faced an almighty South Africa side who were looking to make a statement. The second is they were missing some hugely important players. But, for an Italy team who showed a lot of promise in the Six Nations, to concede 66 points will be tough to take. They don't want to go back to the days when that was the norm and they're a much better side than that.
The good news is now that's out the way, games against Argentina and Fiji give them a chance to bounce back.
12. Fiji
Previous ranking: 12
There's not too much to say for Fiji. To score 17 points against France is somewhat of an achievement here, but they just can't compete at that level at this point in time. Things don't get any easier against Ireland next week before they quickly turn their attentions to Italy.