In front of a vocal home crowd in Ardabil, they won 25-19, 25-19, 25-14 to leave Australia in serious danger of demotion as the lowest-ranked challenger side.

Iran, meanwhile, have won 10 out of 11, and after Poland failed to beat Serbia in straight sets, can no longer fall out of the top six places in the overall rankings, meaning their final spot is secure.

Earlier, France swept to their eighth Nations League win with a straight-sets victory over Portugal, putting them on the verge of qualification for the final round.

They won 25-23, 26-24, 25-23 at Rezazadeh Stadium.

While they cannot catch Iran, Poland still have hopes of making the Nations League final round after beating Serbia in a five-set epic in Pool 14.

In a match lasting nearly two and a half hours, Poland eventually came through 32-30, 21-25, 25-21, 19-25, 15-11 in Milan.

Pool hosts Italy followed at the PalaLido against Argentina, where the South American nation caused an upset by winning 25-22, 23-25, 25-19, 25-19.

It was Argentina's fifth win in 11 which gives them faint hope of a finals place, while Italy's third Nations League loss means they still have work to do.

In Pool 16, Brazil are on the verge of joining Iran in the final-round, although they were made to work hard in front of a home crowd at Ginásio Aecim Tocantins in Cuiabá as they battled to a five-set victory over Germany, 20-25, 25-18, 21-25, 25-17, 15-13.

Earlier third placed Russia moved a step closer to the final with a straight sets win over Bulgaria, 25-20, 25-20, 25-21.

United States, hosts of Pool 13 in Hoffman Estates, Illinois, and the final round in Chicago, were beaten by Canada in a North American clash, 25-22, 22-25, 25-23, 25-17.

This followed an all-Asian match-up between China and Japan, with bottom ranked China falling to another heavy defeat, as Japan won 25-19, 25-20, 25-23.