(Reuters) - South Korea were held to a surprise 0-0 draw by Syria in 2018 World Cup qualifying on Tuesday, while neighbours Japan got their campaign back on track with a 2-0 win over Thailand in Bangkok.

The Koreans, bidding for a ninth consecutive appearance at the World Cup finals, were lucky to hang on for a 3-2 win over China in their Group A opener last week and again failed to shine against Syria, ranked 57 places below them at No. 105.

With Son Heung Min returning to England to fight for his place at Tottenham Hotspur, Korea had little sharpness about them up front and had few clear cut chances in a match played in Malaysia as Syria's civil war means they have to play "home" games at neutral venues.

Ki Sung Yueng and Lee Chung Yong both went close for South Korea, who could easily have been down to 10 men when defender Oh Jae-suk fouled Mahmoud Al Mawas as he broke clear on goal.

Referee Chris Beath opted for leniency and showed a yellow card.

Iran, who drew 0-0 with China, top the section on goal difference ahead of Korea, both on four points, though Uzbekistan can leapfrog them both by beating Qatar in the day's final group game.

In Group B, Japan scored an important victory over Thailand to steady the ship after their shock 2-1 loss to United Arab Emirates in Saitama last week.

Genki Haraguchi (17th minute) and Takuma Asano (75th) got the goals.

Saudi Arabia fought back from a goal down to beat Iraq 2-1 thanks to two late penalties from Nawaf Al Abid.

They moved clear in Group B on six points, but Australia will look to join them when they face the UAE in Abu Dhabi later on Tuesday.