Six Nations 2015: Wales move above Australia in rankings
World Rugby's table shows Wales in fifth, with the Wallabies dropping a place to sixth.
There has been no change elsewhere in the top 10.
Defeated Ireland remain third while England are fourth behind leaders New Zealand. South Africa are second while Scotland stay 10th.
England beat Scotland on Saturday at Twickenham after Wales' tense win over Ireland in Cardiff.
Wales also face hosts England, Fiji and Uruguay in the World Cup.