KUALA LUMPUR: Despite massive recent investment in the game domestically and abroad, China's hopes of qualification for the 2018 World Cup could be dented significantly if the team loses at home to Iran.

A 3-2 loss in South Korea in the opening game of the final round of Asian qualification last week means that a defeat in Shenyang on Tuesday could potentially leave China six points adrift of the top two spots in Group A that offer automatic progress to Russia in 2018.

With more than $400 million spent by Chinese Super League clubs in 2016 on famous foreign players as well as a state-run youth development program gathering pace, there has been growing optimism for the future of the game in the world's most populated country in the long-term. In the short-term, however, much depends on a victory against a tough Iran team — even so early in qualifying.

China was trailing South Korea 3-0 with 20 minutes remaining but goals from Yu Hai and Hao Junmin forced the 2002 World Cup semifinalists to hang on for the final whistle.

And coach Gao Hongbo wants his China team to continue where it left off in Seoul.

"If we can play against Iran with the same spirit as the last part of the last game then we can get a good result," he said. "There are nine games remaining in the group and this is our first home game.

"We need to do well in front of our own fans if we are going to achieve our goal of qualifying for the World Cup."

The comeback last Thursday against South Korea — a team that China has a poor record against with one win in 31 meetings — has boosted confidence and has fans and the domestic media optimistic of better times ahead.

"The result was a defeat but we saw that this Chinese team never gives up," Yu Hongchen, Chinese Football Association vice-chairman, said. "Never give up, never admit defeat is a feeling that is part of this team."

China has only qualified for the World Cup once — in 2002.

Iran arrived in the northeastern city of Shenyang after a long chartered flight from Tehran. The Iranians, coached by former Real Madrid boss Carlos Queiroz, are coming off a 2-0 win over Qatar 2-0 that was only sealed with two injury-time goals.

"We are expecting a tough game against a strong team," Queiroz said. "To qualify for the World Cup, you have to pick up points away from home and this is what we are hoping to do."

In the other Group A games, Qatar hosts Uzbekistan while security issues mean Syria will play South Korea in Malaysia.

If China is already under serious pressure to win in Group A, then so is Japan in Group B. The four-time Asian champion has qualified for the last five World Cups but had a shocking 2-1 home loss to the United Arab Emirates last week.

Keisuke Honda had put Japan ahead but two goals from Ahmed Khalil gave the UAE a famous come-from-behind victory.

There was controversy as a shot from Japan striker Takuma Asano seemed to cross the line — but the Qatari referee did not award a goal.

The Japan Football Association has gone to FIFA, the sport's international governing body, to intervene.

"We filed a protest ... immediately after the game, with a claim that the shot should have been judged as a goal," JFA spokesman Futoshi Nagamatsu said.

Honda told reporters that there should have been extra officials on the field as is the case in the UEFA Champions League.

"I was right at the side of the goal, so I know it was in," the AC Milan player said. "I question why they did not have an (extra) referee for the final round of qualifying, in which the levels of competition are high."

Japan is in Bangkok to take on a Thailand team that narrowly lost 1-0 in Saudi Arabia. The UAE faces another stiff test at home against Asian Cup champion Australia. The Socceroos opened with a 2-0 win over Iraq in Perth, Western Australia. Iraq and Saudi Arabia meet in the other game.