The Socceroos failed to win any of their three matches, with their best result a scoreless draw against hosts South Korea.
 
But losses to Japan (3-2) and China (4-3) ensured Australia ended up on the bottom of the table with only point which means they dropped from 40th to equal 46th, along with Wales, in the global standings.
 
Meanwhile, the United States have moved back into top 20 after winning the CONCACAF Gold Cup.
 
Juergen Klinsmann's men, who won the Gold Cup with a 1-0 triumph over Panama in Chicago last month, jump three places to 19.
 
Panama are into the top 50 thanks to their strong showing in the Gold Cup, moving 11 spots up to 40.
 
USA are one spot below Ivory Coast, who fell five places to 18, with Bosnia-Herzegovina, England, Switzerland, Russia and Ecuador all benefiting from their demotion.
 
FIFA World Cup and UEFA European Championship holders Spain remain the best team on the planet as the top 10 stayed unchanged.
 
Germany are second, with Colombia, Argentina and the Netherlands rounding off the first five places.
 
Cape Verde Islands are among the big movers, with Lucio Antunes' side rising from 49 to 36.
 
Honduras, semi-finalists at the Gold Cup are up 12 spots to 43, while Cameroon are now at 51 following a 20-place jump.
 
South Korea are the major fallers of the month, plummeting 13 places down to 56 after failing to win a game in the final round of the East Asian Cup.