South Korea confirmed their place in the next round of Asia's World Cup qualifiers with a 7-0 thrashing of hosts Singapore on Thursday while debutant Behram Abduweli kept China on track with a late equaliser in a 1-1 draw with Thailand in Shenyang.
The win moves the Koreans onto 13 points from five games and guarantees them first place in Group C with one match remaining.
The top two in each of the nine qualification groups advance to the next phase in the quest for one of Asia's eight guaranteed berths at the 48-team World Cup in Mexico, the United States and Canada.
Lee Kang-In gave the Koreans the lead in Singapore with a rising shot into the roof of Hassan Sunny's goal in the ninth minute before Joo Min-kyu's header doubled the advantage 11 minutes later.
Captain Son Heung-Min scored twice after the interval, either side of a second for Lee while Bae Jun-Ho and Hwang Hee-Chan were also on target in interim coach Kim Do-hoon's first game in charge.
China's Abduweli scored a late equaliser to boost their prospects of a place in the next round with Branko Ivankovic's side picking up a precious point despite Fei Nanduo's first half penalty miss.
Supachok Sarachat had put the Thais ahead with a 20th minute header before naturalised Brazilian Fei Nanduo fired over the bar in 51st minute.
But Abduweli swept his effort past substitute goalkeeper Saranon Anuin with 11 minutes left as China stayed in second place, three points ahead of Thailand with one game remaining.
In Hanoi, Vietnam kept their slim hopes of advancing alive with a 3-2 win over the Philippines in Group F to move to within a point of Indonesia, who slipped to a 2-0 loss against Iraq.
Jesus Casas' Iraq side had already secured top spot but a penalty from Ayman Hussein and Ali Jasim's late effort took the points against a home side reduced to 10 men in the 59th minute when captain Jordi Amat was sent off.
Already-qualified Japan maintained their unblemished record in Group B as Koki Ogawa scored twice in a 5-0 win in Yangon over Myanmar while Oman boosted their chances in Group D with a 3-0 victory over Taiwan.
Australia also remained perfect with a 2-0 win in Dhaka against Bangladesh in Group I and Mehdi Taremi scored a hat-trick in Iran's 4-2 success against hosts Hong Kong in Group E.