France made it two wins from two while Italy have named their team for their huge clash with South Africa on Friday.
Elsewhere Ireland are looking to history for good omens while England are ready for an aerial bombardment.
With quarter of an hour remaining France only led by three points but in the end Jacques Brunel’s team were able to see off the USA challenge in a 33-9 success in Fukuoka.
Late tries from Gaël Fickou, Baptiste Serin and Jefferson Poirot added some gloss to the scoreline in a game that was starting to get quite tense for France.
Camille Lopez’s kicking game had helped set up Yoann Huget and Alivereti Raka for tries early on, but after leading 12-6 at the break, Les Bleus struggled to pull away, with indiscipline and handling errors hurting them.
The impact of the bench helped for the second game running however, and with Serin raising the tempo, Fickou’s try 13 minutes from time appeared to liberate them.
The replacement scrum-half finished off a fine attack that started with another Lopez cross-kick before Poirot went over from a rolling maul.
The win puts France on nine points from two games, with a quick turnaround to come as they face Tonga on Sunday. Were England to beat Argentina the previous day, a win would be enough for France to clinch a quarter-final spot.
Sergio Parisse is back for Italy in their big match-up with South Africa as they look to reach the quarter-finals of the World Cup for the first time.
The Azzurri face the Springboks in Shizuoka with just three changes from the team that beat Canada last time out.
Luca Morisi replaces Giulio Bisegni in the side, with Morisi slotting into the centres as Michele Campagnaro shifts out to the wing.
Meanwhile Tito Tebaldi is back at scrum-half in place of Callum Braley, with Parisse replacing Sebastian Negri in the back row, Braam Steyn switching back to the flank.
That means that Jayden Hayward continues at inside centre, a position which he played for the first time at Test level in the success against the Canadians.
However Hayward insists he is comfortable in the midfield, even though he has spent most of his Test career at full-back.
He said: “In New Zealand, I played all my rugby at 12 so it is not a foreign position to me. As long as I’m involved, I’m not too fussed where I play.
“South Africa are a very direct team, so we are going to have to front up and be physical.”
Anthony Watson has been one of the standout performers for England this Rugby World Cup and the Bath player is expecting to be put through his paces against Argentina.
Comfortable both on the wing and at full-back, Watson started the opening win against Tonga before coming off the bench against the USA.
The challenge gets even tougher this weekend in Tokyo against Los Pumas, and Watson is expecting the Argentina back three to turn to the boot as an attacking weapon.
He said: “They like to kick both contestable and long and we have seen at the World Cup how important the high ball is. We will be ready for that. If they kick loosely to us, we will be ready. We back our counter-attack skills.
“We spent time in Treviso so we prepared for (sweat on the ball) in similar conditions. We are quite used to the ball being slippy. You just have to concentrate more on technique. It just highlights areas you have to work on.
“(To counter cross-kicks) you have to be completely aware of the positioning of your opposition wing or full-back, keep looking up and communicating with your backfield players to make sure someone is covering, or you are.
“Space does appear at times and you have to react to either take advantage or nullify it. Wingers have to communicate with the guys inside them to let them know where there is space so they can execute the kicks to where you want them.”
The line about no team ever losing a pool game and going onto win the World Cup has been bandied about a great deal over the last fortnight.
From an Ireland perspective, it means that they will have to break new ground if they are to lift the World Cup, but defence coach Andy Farrell insists there is also reason for optimism when looking at past performance.
While it is true that no team has won the tournament after losing a game, each of the last three World Cups have seen a team come close to doing so.
And following the 19-12 defeat to Japan, Farrell believes that Ireland have to turn that disappointment to their advantage.
He said: “You can use a setback in the right manner. You can look at the last three World Cups. South Africa lost to Japan and lost the semi-final (to New Zealand) 20-18. You look at 2011 – France looked in disarray and there’s a debate about whether they should have won the final.
“In 2007, I was part of the England squad that got a thrashing against South Africa. There was a bit of turmoil in that camp and they managed to get to the final. There was a debatable try that was disallowed. You can use these to your advantage, they’re not ideal, but if you use them to your advantage they can be powerful.
“After a couple of days of understanding the reasons why, we’re in good spirits – back on track and ready to prove a point.”
It was an intense start to the World Cup for Wales who saw off Georgia and then six days later got the better of Australia in their biggest pool game of all.
After that 29-25 success, Warren Gatland’s team had a little break before matches against Fiji and Uruguay, with the plan to give them a little break to recharge the batteries.
Wednesday was identified as an optional day off, but the Wales squad decided they wanted to train as they look to build on the momentum of their opening two successes.
And for forwards coach Robyn McBryde, it was typical of the squad of players he has at his disposal.
He said: “There is competition within the squad and everybody realises what is at stake. We have got a bit of momentum, a bit of a wind in our sails, and the boys are just keen to keep that going.
“It’s a Welsh mentality as well. When you down your tools, it’s sometimes very hard to pick them up again and you lose that momentum. It’s just keeping on top of things and making sure we give ourselves the best opportunity against Fiji.”
A bonus-point success over Samoa got Scotland’s World Cup campaign back on track, but they now face the daunting challenge of taking on Russia and then Japan over the space of four days.
Gregor Townsend’s team have another week before they take on the Bears, but will then have to immediately get ready for taking on the hosts in their final pool game.
Scotland need to win both games, possibly with a bonus point, to reach the quarter-finals and despite the quick turnaround, Greig Laidlaw is confident they will be firing when it matters.
He said: “Each game is going to be different. Russia have been impressive so far so we have got to get that game right.
“We’ve got an excellent squad here and it’s going to take a squad effort for us to get the two strong performances we need to get through.
“That’s going to be vitally important. We’ve got boys that are hungry to play and I think if it comes to it you could do it (play twice in four days) because we want to get into the quarter-finals.
“If we were on the Japanese side then of course we’d be happier with their turnaround.
“But we’ve known about this for a long time and have prepared with the S&C staff, the physios and the coaches so the boys know what’s coming.
“The boys have to look after themselves. We need to get the Samoa game out of our system quickly and then move on to that Russia game.
“We’ll have some excellent preparation for that but I’d imagine we’ll be doubling up a little bit. We’ll certainly not look too far ahead.”