Uzbekistan thrashed Qatar 4-0 to keep its hopes alive while Japan moved to the top of the group with a 1-0 win over Bahrain.

The results mean that if the Socceroos can beat Uzbekistan on Wednesday and Bahrain and Qatar draw their match, the Australians will be the first team to qualify for the World Cup in South Africa.

Celtic midfielder Shunsuke Nakamura scored the only goal of the game as Japan overcame Bahrain.

Nakamura's 47th-minute strike handed the hosts all three points at Saitama Stadium and means Japan climb to the top of their group with 11 points.

Japan dominated from the start as the lively Tatsuya Tanaka fired wide of the goal in the third minute before Yuji Nakazawa's header was cleared off the line by Mohamed Hubail in the 25th minute.

Bahrain were defending in numbers and were frustrating the Japanese before Nakamura broke their resolve with a somewhat fortuitous strike.

Japan won a free-kick just outside the area two minutes after the break and, after being teed up by Yasuhito Endo, Nakamura struck an effort towards goal that got a big deflection off defender Abdulla Marzooq and looped over the goalkeeper.

Atsuto Uchida wasted a good chance to add a second in the 54th minute when he was found unmarked in the box by an Endo cross, but his first touch was poor and Bahrain cleared the danger.

Tanaka's shot was saved by Sayed Mohamed Jaafar after picking up a pass from Nakamura before the bar then denied Japan when Uchida's drive rattled the woodwork in the 64th minute.

Bahrain, meanwhile, were well contained on the few occasions they ventured forward and, with the clock running down, Shinji Okazaki took the ball into the corner to make sure there was no late drama.

Uzbek striker Farhod Tajiev was the hero in Tashkent with a hat-trick, while Anvarjon Soliev also added his name to the scoresheet.

Qatar's hopes of an important away win were dashed on 32 minutes when defender Bilal Rajab was sent off for aggressive behaviour.

The send-off was the instigator the opener when Tadjiev got his first just two minutes later when he converted a close range header.

Tadjiev got his second in the final stages of the first half with another header from a Jasur Hasanov cross.

The forward then completed his day out with another header before Soliev completed the rout.