North Korea beat Japan 1-0 in a tempestuous World Cup qualifier on Tuesday, the result largely academic with the visiting Blue Samurai already through to the final qualifying round for 2014.

Pak Nam-chol headed the winner in the 50th minute, and the final whistle sparked wild celebrations at Pyongyang's Kim Il-sung stadium despite the fact North Korea had already been eliminated.

"We didn't do anything right for 90 minutes," Japan defender Yasuyuki Konno said. "They dominated us. We were pathetic."

Under the gaze of a giant portrait of North Korea's 'Eternal President' Kim, Japan's national anthem was drowned out by boos before a fractious Group C match.

Matches between the two invariably take place against a backdrop of political tensions over World War II, North Korea's nuclear ambitions and the kidnapping of Japanese citizens.

Japanese nationals are normally asked to refrain from travelling to the secretive communist state after sanctions were imposed following North Korea's missile launch in 2006.

Japan's players had received a typically frosty welcome on landing at Pyongyang on Monday. They were detained at customs for four hours while airport officials combed through their luggage.

Although a dead rubber, tempers frayed after Pak's goal with Jong Il-gwan being sent off for a second bookable offence in the 77th minute after a nasty tackle on Atsuto Uchida.

Asian champions Japan, who have 10 points from five matches, lost for the first time in 17 games under Italian coach Alberto Zaccheroni.

"They were very physical and made it very difficult," the Italian said. "North Korea had failed to qualify for the last round so this will be some consolation for them."

Victory also gave North Korea payback for a 1-0 injury-time defeat in Japan in September. Uzbekistan will join Japan in the final round of qualifiers from Group C.

Later in the day lowly Lebanon stunned Asian heavyweights South Korea 2-1 in Beirut to leave them on the brink of advancing to the fourth round of World Cup qualifying.

A 31st minute penalty by forward Abas Atwi proved the difference as the 146th FIFA-ranked produced a resolute defensive display to hold off their more illustrious opponents.

Fans ran on to the pitch at the Camille Chamoun Sports City Stadium at the sound of the final whistle with some Lebanese players in tears after recording their first win over the former Asian champions.

The two sides are locked on 10 points from five matches in Group B of the third round of Asian World Cup qualifiers and both will take one of the 10 places available in the fourth round should Kuwait fail to beat United Arab Emirates in the other pool match later on Tuesday.

South Korea had beaten Lebanon 6-0 at home in September but they struggled to establish their normal high-tempo slick passing on the bumpy, hard pitch with the blustery wind also proving a factor.

Without their suspended captain and leading striker Park Chu-young, the Koreans fell behind after five minutes when Ali Al Saadi lashed home an unstoppable drive from six yards after he had blocked his team mate Roda Antar's shot.

The creative Koo Ja-cheol soon brought the Koreans level from the spot but his clumsy waist-high challenge on Mahmoud El Ali gave away the penalty that resulted in the winning goal.

Former Asian champions Iraq reached the fourth round thanks to two goals from Nashat Akram which ended China's slim hopes of advancing despite a crushing 4-0 away win over Singapore.

Iraq, coached by Brazilian great Zico, have 12 points in Group A, level with Jordan who booked their fourth round place on Friday.

Their near neighbours and rivals Iran made it through to the fourth round after three goals in the opening 24 minutes set up a 4-1 victory over an experimental Indonesian side in Jakarta.

Iran's passage from Group E was secured when 2022 World Cup hosts Qatar were held to a goalless draw by gulf rivals Bahrain at the air-conditioned Al Sadd Stadium in Doha.

Reuters