Syria's 2-0 win against Lebanon kept them atop Group D with their second win in as many matches but Pim Verbeek's weakened Socceroos side could manage only a point against a determined Indonesia in their opening Group B match in Jakarta.
Newly crowned Gulf champions Oman secured a 1-0 win away to Kuwait to take the Group B lead and Bahrain stayed top in Group A, maintaining their unbeaten record with a 1-0 win over Japan.
In Bangkok, three-times Asian champions Iran, who thumped Singapore 6-0 in their opening match, had to work hard for the point against a tenacious Thai side who attacked relentlessly.
The visitors almost went ahead 11 minutes into the match when Mageed Gholamnejhad's stunning volley from 30 metres was tipped on to the post by the Thai keeper.
The Thais came close to scoring through Datsakorn Thonglao, Suree Sukha and Suchao Nutnum but their taller, stronger opponents stood firm against a second-half onslaught.
TOUGH MATCH
"I said before the match this was going to be tough," Iran coach Ali Daei told reporters.
"We didn't come here for a point, we wanted all three but my team played very well. We can't win all our games -- this happens in football," added Daei, who is the world's all-time highest international scorer with 109 goals in 148 appearances.
Singapore moved second in Group E with a 2-1 win over Jordan. Abu Casmir gave the Lions the lead on 21 minutes and Hatem Aqel levelled for Jordan close to the break.
Singapore grabbed the points just after the hour when prolific forward Noh Alam Shah slotted home from inside the area.
Indonesia dominated their match with Australia, group leaders in World Cup qualifying, who struggled without their top European players.
"I don't think we deserved to win this game," Socceroos coach Verbeek told reporters. "The draw was the best result."
Salman Isa Ghuloom secured the win for Bahrain over a below-par Japan. Farhad Tadjiyev netted the only goal of the game to give Uzbekistan a 1-0 win over United Arab Emirates in their opening Group C match.
