Australia's Olympic hopes were dealt a major blow with away defeat to Uzbekistan late on Sunday, while Japan were knocked off the top of Group C with an upset loss to Syria.
UAE beat Iraq 1-0 in Doha thanks to an early strike by Al Abri.
South Korea needed an injury-time equaliser to scrape a 1-1 draw against unfancied Saudi Arabia, while Southeast Asian Games champions Malaysia remained winless in four outings as they lost 2-1 to Bahrain.
But Aurelio Vidmar's 'Olyroos' were the biggest losers as they crashed to the bottom of Group B with a 2-0 loss in freezing Tashkent, leaving them five points off the lead with two games to play.
Only the top teams in each of three Asian groups gain automatic berths for this year's London Games, while three second-placed teams will compete for a play-off spot.
Australia went down 2-0 through goals from Kenja Turaev and Oleg Zoteev either side of half-time, meaning they are still yet to find the net in their four qualifiers so far.
In temperatures of minus 12 degrees Celsius (10.4 Fahrenheit), Jason Hoffman had a goal ruled out for offside while a Mitch Nicholls's effort was disallowed for a foul in the penalty area.
In Amman, Japan were rocked by an early Yuya Osako own-goal before Kensuke Nagai got them back on terms just before half-time. But defender Ahmad Al-Salih clinched it 2-1 for underdogs Syria with his winner on 90 minutes.
With the victory, Syria take over as Group C leaders due to their superior tally of goals scored compared with Japan, who are also on nine points.
Meanwhile Kim Bo-Kyung spared South Korea's blushes as he cancelled out Omar Sultan Khudari's opener for Saudi Arabia in the first minute of injury time in Dammam.
The draw was enough to preserve South Korea's slender one-point lead at the top of Group A after Qatar and Oman drew 2-2 in Doha.
Asian zone Olympic qualifying results played on Sunday:
Qatar 2 (Al Bulshi 26, Al Haydos 86) Oman 2 (Al Maqbali 34, Farah 76)
Saudi Arabia 1 (Kudari 60) South Korea 1 (Kim Bo-Kyung 90)
Iraq 0 UAE 1 (Al Abri 3)
Uzbekistan 2 (Kenja 27, Oleg 65) Australia 0
Syria 2 (Yuka o.g. 19, Al Salih 90) Japan 1 (Kensuke 45)
Bahrain 2 (Alawi 25, Al Fahran 88) Malaysia 1 (Bin Bakri 85)
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