HANOI (AFP) -- Australian captain Mark Viduka has credited widespread criticism at home of their early struggle in the Asian Cup for driving them to a quarterfinal against defending champions Japan.

""We deserved to be criticized over the way we played,"" the Newcastle United striker said about Australia's 1-1 draw against Oman and 3-1 loss to Asian stalwarts Iraq in their first group games. ""And I think a lot of us felt that the criticism started to grow beyond football,"" he added. ""They were criticizing us in Australia for things not related to football at all. It was very disappointing."" Reports in Australia suggested that there was a rift among the players. The Socceroos, partly blaming their poor form on hot and humid weather, finally exploded with Viduka striking twice and Michael Beauchamp and Harry Kewell putting away one each to beat co-hosts Thailand 4-0. ""We all knew before the (Thailand) game that we needed a good result and I think it pulled us together,"" said Viduka. ""The criticism sort of put us in some sort of the same boat and gave extra motivation to us,"" added the 31-year-old. He said Japan were definitely favorites today but that his side were ""quietly confident."" Australia coach Graham Arnold added: ""Maybe the first two games against Oman and Iraq shocked the players in showing how difficult the tournament is. ""You are going to have to come up against one of the favorites some time and I'm quite happy to come up against them now. ""Australians love to be underdogs. We had our first final against Thailand, we came through that, and this is our second one."" Viduka said he was determined to score more goals. ""Obviously it is always a good thing for a striker to score goals,"" he said. ""It's always a confidence factor when you do score goals for any player really, striker or non-striker, and obviously I feel a lot more confident.