Wales, South Africa, France and Italy all posted wins in pre-World Cup friendlies at the weekend.
Below are the match reports from Reuters.
WALES 13 ENGLAND 6
Wales beat England 13-6 in Cardiff on Saturday to avenge their loss in the reverse fixture last weekend and thrust themselves to the top of the official world rankings.
Wales' rise to the summit, which ended New Zealand's unbroken 10-year occupation, comes just 34 days before the World Cup kicks off in Japan.
It was an impressive warm-up performance for the global tournament as they reeled off an 11th successive home win.
A fired-up Wales, fielding a near full-strength side against a more mixed England line-up for the second game in a row, scored the only try of an error-strewn encounter through winger George North.
Fly-half and man-of-the-match Dan Biggar, in the spotlight following injured Gareth Anscombe being ruled out of the looming World Cup, impressed with a smart cross-field kick for North's try after England's Anthony Watson had been yellow-carded.
Wales head coach Warren Gatland was pleased with the character shown by his side in the match.
"I said to the boys in the changing room we have to show massive character as we had to dig pretty deep and lost two second rows, so we had four front rowers on," Gatland said.
"We showed some brave character and that's what we're about. If you want to beat us you have to play pretty well."
When asked how he thinks Wales will fare away from Cardiff in the World Cup, the New Zealander added: "I think we've done a good job of winning over the support of a few Japanese fans.
Wales captain Alun Wyn Jones played down reaching the rankings summit and said he was "just" satisfied with the performance against England.
"We're a team of 3.3 million, so we can be happy with that," Jones said of the ranking.
"Satisfied - just. The first half was a definite improvement (on last weekend). There were probably patches in the second half where we dropped a little bit.
For England, the main positive of a stodgy performance will be the fact they emerged unscathed on the injury front, apart from the pre-game withdrawal of winger Ruaridh McConnochie.
And their captain George Ford said he won't read too much into the result with the World Cup just around the corner.
"I can't fault the effort of the lads. What we have to do is to come back. That was a proper Test match. Very physical, not much time and space on the ball," he said.
"It's good for us to play at a stadium like this with the roof closed. We will keep working.
"I don't think many people remember these games. What happens at the World Cup in a few weeks' time will be completely different."
SPRINGBOKS 24 PUMAS 18
Sibusiso Nkosi scored two brilliant tries as South Africa beat Argentina 24-18 on Saturday in a Rugby World Cup warm-up match in Pretoria.
The winger struck in each half for the Springboks, who found the going much tougher than last weekend when they hammered the Pumas by 33 points in Salta to win the Rugby Championship.
South Africa have an embarrassment of riches on the right wing with Nkosi and Cheslin Kolbe, who was rested for this match, bidding to start against New Zealand in Japan on September 21 in their World Cup opener.
All the other South African points at Loftus Versfeld came from fly-half Elton Jantjies, who kicked a conversion and four penalties.
Forwards Guido Petti and skipper Pablo Matera each scored a try for Argentina. Joaquin Diaz Bonilla kicked a conversion and a penalty and Benjamin Urdapilleta a penalty.
South Africa skipper and flanker Siya Kolisi showed no ill effects from a knee injury sustained last May before coming off after 53 minutes of his first international appearance this season.
Although Argentina suffered a ninth consecutive loss, there was encouragement for coach Mario Ledesma from a much improved scrummaging performance, that won several penalties.
The Pumas thought they had taken the lead with three minutes left when debutant Lucas Mensa touched down, but the try was disallowed for obstruction by fellow centre Jeronimo de la Fuente.
"I needed Siya Kolisi a lot and it was great to see him back on the pitch," admitted skipper Schalk Brits, who is set to be the third choice World Cup hooker behind Malcolm Marx and Bongi Mbonambi.
"Argentina made it very difficult for us, but we scraped through. We played a bit too much in our own half."
Matera said: "I'm really happy with the effort. We had a couple of other chances for tries.
"I think we were stronger than the Springboks in the scrums, but we had a few problems in the lineouts."
FRANCE 32 SCOTLAND 3
France have blown away away Scotland 32-3 in a Rugby World Cup warm-up match on Saturday.
In a first hit-out for both teams, the French looked far more ready and hit the ground running.
They scored five tries, the first in only the second minute.
A Scottish throw-in went through the intended catcher's hands, France countered, and winger Alivereti Raka on debut angled in to crash over beside the posts.
It was the third time in four matches Scotland has conceded a try early.
It got only better for France, who outclassed the Scots across the park and posted 30-plus points against a team other than Italy for the first time in nearly three years.
Camille Lopez added a penalty earned from their superior scrum, and quick ruck ball gave right wing Damien Penaud an overlap to put in fullback Maxime Medard.
Adam Hastings slotted a penalty for Scotland's only points, then was sin-binned moments later for blocking a pass.
France took advantage by setting up a lineout maul, and No.8 Gregory Alldritt peeled off to score his third try in two games against Scotland this year.
That made it 20-3 at halftime, which came as a relief for the Scots.
The visitors were stressed in the tight and loose, and it didn't take long in the second spell for coach Gregor Townsend to debut centre Rory Hutchinson and lock Scott Cummings around Medard's second try from quick hands.
Scotland had a try by Huw Jones disallowed for a forward pass, and France finished with a score by scrumhalf Antoine Dupont.
France go to Murrayfield for the return match on Saturday.
ITALY 85 RUSSIA 18
Italy submitted Russia to a humbling 85-15 defeat on Saturday, running in 13 tries in their final home appearance before the Rugby World Cup.
Matteo Minozzi led the scoring with three tries at the Stadio Riviera delle Palme in San Benedetto del Tronto as Italy's back division ran riot.
Captain Sergio Parisse was also among the try-scorers as Italy reached halftime 38-8 ahead.
The pace did not drop as Tommaso Allan, who kicked six conversions, went over within a minute of the restart. Other notable performances came from Mattia Bellini and Edoardo Padovani, who both claimed a couple of tries.
Italy travel to France and England for further warm-ups before heading for the World Cup. They face Namibia, Canada, South Africa and New Zealand in Pool B.
Russia, ranked 20th in the world, face Japan, Samoa, Scotland and Ireland in Pool A.
Their opening game against hosts Japan launches the tournament in Tokyo on 20 September.