Indonesia coach Benny Dollo admitted his team were surprised by the positive approach shown by Cambodia.

The Indochinese side were hammered 5-0 by Singapore in their opening match in Friday and were expected to adopt a defensive outlook for their clash with the Group A hosts.

But the Cambodians were not content to sit back and offered a few scares themselves before eventually succumbing to a 4-0 defeat.

"We really thought they would play defensively, so when they did otherwise, the boys were surprised and lost concentration, but only for a short while," said Dollo.

A Budi Sudarsono hat-trick and a late header by Bambang Pamungkas eventually settled the matter for the Indonesians, who booked their place in the semi-finals with the win.

But their failure to find the net for a fifth time means that they trail Singapore on goals scored and must win their final game against the defending champions on Tuesday to secure top spot and a home game in the second leg of the semi-finals.

Dollo though was not too concerned about the mathematics of the situation.

"The question of one goal or not does not arise. We still have to play them (Singapore) on Tuesday so let's wait till then.

"Singapore are the favourites but certainly, we want to win the match too. Our players are inspired and they will give their best."

Singapore booked their place in the last four with a 3-1 victory over Myanmar.

Goals by Noh Alam Shah and Agu Casmir in the first 16 minutes put the Lions in control but Myo Min Tun's first-half strike kept the game in the balance until Casmir struck a controversial third 16 minutes from time to extend Singapore's unbeaten run in the competition to 19 games.

"We started well. But I think the second goal came a little too early as it caused the players to be too comfortable and that allowed Myanmar to come back at us," said Singapore coach Raddy Avramovic.

Myanmar were left aggrieved by the referee's decision to allow Singapore's third goal to stand after a quickly-taken free-kick.

Goalkeeper Aung Aung Oo was shown the red card for pushing Vietnamese referee Phung Dinh Dung in the back after Casmir tucked the ball away and the Myanmar players did not help their cause by angrily surrounding Dung to remonstrate.

Coach Carlos Antonio Falopa would not be drawn into commenting on the situation.

"I could not see well from where I was," the Brazilian said. "I have to review and analyse the video first.

"The first goal affected our game but I was happy with the way the boys fought back especially in the second half," he added.