Italy boosted their World Cup hopes with a vital bonus-point win Tuesday as Japan's tournament ended on a low and France were forced to deny rumours of a player mutiny against their outspoken coach. England warned their campaign was under threat from a desperate Scottish team and injury-riddled Australia lost number eight Wycliff Palu to a hamstring problem as tension built ahead of this weekend's final pool games. Italy were the big winners after a turgid 27-10 victory against USA which yielded the all-important four tries, earning the extra point which puts them level with Australia before Sunday's clash with Pool C leaders Ireland. The Italians scored three in the first half through Sergio Parisse, Luciano Orquera and Martin Castrogiovanni, but they had to wait 26 minutes into the second period before referee George Clancy blew for the crucial penalty try. "It was a tense build-up to this game because I respect what USA have done in this tournament," said Italy coach Nick Mallet. "But our major advantage is our scrum and we dominated them completely. I'm sorry for the spectators, it might not have been as open as they would have liked, but you play to your strengths." The United States bowed out after a creditable campaign which included a battling defeat to Ireland and a 13-6 victory over World Cup debutants Russia. "You can tell they're a Six Nations team and they've gotten some wins because they know what to do under pressure," USA captain Todd Clever said of Italy. "We've given what we had but in the end it wasn't enough against a strong side tonight." Japan's World Cup dream ended cruelly in a 23-23 draw with Canada, after a 79th-minute penalty snatched away what would have been only their second win in the tournament -- and their first in 20 years. The deflating result, which compounded the 2019 hosts' disappointment at missing their target of two wins in New Zealand, left their coach John Kirwan admitting that he was considering his options. "I'm off-contract. I'm going to take a few weeks off and look at some options, probably wait until the end of the World Cup," said the ex-All Black. "Clubs in Europe, coming home to New Zealand, or staying with Japan, they're all options," he added. Australia's injury-hit campaign took a turn for the worse with the news that Palu was flying home, while England admitted they were wary of old rivals Scotland who will be fighting for their lives in Pool B on Saturday. "It's going to be a tough game. Scotland have their backs against the wall and they'll want to come out fighting," said prop Matt Stevens. "We've got to take that next step up with our physicality and our discipline and we've been working hard at that." And France quelled rumours of an uprising along the lines of their 2010 football World Cup debacle after reports said players were growing disenchanted with outspoken coach Marc Lievremont. Former captain Lionel Nallet called the idea "nonsense" and insisted relations were cordial, despite Lievremont's public criticism of some players and his outburst last week when he told a journalist to "go to hell". "I have been hearing stories, rumours about little uprisings by the players and a lot of nonsense like that," said Nallet. "At the moment there is a very good atmosphere in our squad and we are all united with each other."