Two goals by Naohiro Takahara and a Shunsuke Nakamura penalty put the three-time champions in complete control with a 3-0 lead at half-time.

Things got worse for Metsu's side as Basheer Saeed was dismissed for a lunging tackle on Keita Suzuki, but the Emirates did salvage some pride with Saeed Alkas netting a consolation goal.

The Frenchman felt that Takahara's opening goal in the 22nd minute was crucial.

"Many things happened after the first goal," Metsu said.

"We played well against the Japanese team. But after the first goal, the game changed.

"You give away an easy goal for the first one and the second one again when the positioning of our players went wrong.

"I think Japan has many players with quality, but if you make no mistakes anything is possible.

"But we are a young side and we made many mistakes."

Metsu, who took Senegal to the quarter-finals of the 2002 World Cup, pointed out that his side is young and a very different team from the one that emerged victorious at the Gulf Cup in January.

He said: "From our Gulf Cup victory, we missed six players and it is impossible to win something.

"We also had only one month to prepare for this tournament after our league finished [in May]. We didn't have enough time to prepare.

"Our players tried to do their best but it was not easy for this team."

Meanwhile, Japan coach Ivica Osim was a relieved man as his side overcame the hot and humid conditions at My Dinh National Stadium for a crucial three points.

He said: "The weather condition was so tough that I was so pleased that our players and coaching staff were able to finish the game without suffering a heart attack.

"The team which could make their opponents run more controlled the outcome of the game, and we made them run more than they made us run.

"By scoring first, we were able to take control of the pace. But if UAE had scored first, things would have gone differently and they might have made us run harder."