Asian champions Australia eased to a 2-0 victory over Iraq in Perth as regional powerhouses Japan suffered a shock 2-1 home defeat to United Arab Emirates in 2018 AFC World Cup qualifying on Thursday night.
The first matchday of the third round qualification also saw South Korea survive a late comeback to beat China 3-2 in Seoul.
The Socceroos were made to work hard by the 2007 Asian champions in Group B, relying on two goals in four second-half minutes as Massimo Luongo (61st) and Tomi Juric (65th) struck in quick succession.
Earlier, the home nation was twice denied by the woodwork, as Mathew Leckie and Aaron Mooy hit the bar either side of half-time.
In Saitama in another Group B game, Japan seemed on course for a routine victory when Keisuke Honda headed home after only 11 minutes.
But the UAE, who knocked Japan out of the 2015 Asian Cup quarterfinals on penalties, were back on level terms eight minutes later after Ahmed Khalil's free kick slipped by Japanese goalkeeper Shusaku Nishikawa.
And the Emiratis took the lead in the 54th minute when Khalil, the reigning AFC Player of the Year, slotted home a penalty after Shinji Kagawa and Ryota Oshima had upended Ismail Al Hammadi in the box.
Japan were unlucky not to earn a draw. A shot from Takuma Asano looked to have crossed the line but was not given, Leicester City striker Shinji Okazaki hit the bar and substitute Takuma Asano was denied by Khalid Eisa,
But UAE held on a famous victory that gets their Group B campaign off to a flying start.
China, who haven't appeared at a World Cup finals since 2002, had high hopes, going into their third round opener in Group A. But they were made a poor start against Uli Stielike's Koreans at the Seoul Olympic Stadium, falling behind in the 21st minute after an own goal from Zheng Zhi.
South Korea seemed to be cruising to victory with second-half goals to Lee Chung-Yong (63rd minute) and Koo Ja-Cheol (66th).
But they switched off in the last 15 minutes, allowing China to get back into the game. The visitors capitalised on some sloppy defending, with quickfire goals to Yu Hai and Hao Junmin in the 74th and 77th minutes.
In Riyadh, Southeast Asia's lone representatives Thailand suffered a heart-breaking 1-0 defeat to Saudi Arabia in Group B, wiht Nawaf Al-Abid striking the winning goal in the 81st minute for the home side.
After Kiatisuk Senamuang's side were denied two penalty claims in the first half, referee Fu Ming awarded the hosts a spot kick with less than 10 minutes remaining after Sarach Yooyen's foul on Fahad Al-Muwallad.
Added-time goals from Reza Ghoochannejhad and Alireza Jahanbaksh gave Iran a late 2-0 win in Group A over Qatar in Tehran.
Substitute Reza Ghoochannejhad seized on a mistake by Qatar goalkeeper Amine Lacomte to give the Iranians the lead four minutes into injury time before Jahanbaksh put the result beyond doubt with a long-range effort.
In the other game in Group A, Uzbekistan defeated Syria 1-0 in Tashkent. Old warhorse Alexander Geynrikh got the only goal of the game with 16 minutes remaining.