ABU DHABI: India made a storming start to their Asian Cup campaign with a 4-1 thumping of Thailand in Abu Dhabi on Sunday, but coach Stephen Constantine has urged him team to temper celebrations and focus on qualifying for the knockout stages.

Constantine's men marked their return to the continental showpiece event after an eight-year hiatus with a brilliant second half display to secure a surprise triumph against the more-fancied War Elephants to move top of Group A.

"We try to win every match that we play in," the English coach told reporters after India, who were fortunate to go into the break locked at 1-1, registered a first victory at the tournament in 55 years.

"We don't go into a match expecting to win 4-1 or 5-1. However, we are not trying to get carried away with the emotion.

"We still have two games left and we still need another two points to qualify from the group stages. After we have qualified, we can get a little bit excited, but our primary job is still to qualify out of the group stages."

Constantine attributed his team's slow start to "nervousness" and took heart from their second half display when they scored three times without reply to add to a contentious first-half penalty.

"It was important to not concede a goal in those minutes and that is what we did," the 56-year-old, currently in his second stint with India, added.

"The main thing was to make the most of our chances and that we did. I am happy that we are converting from the chances that we are making."

Talismanic striker Sunil Chhetri, who scored twice, was already looking ahead to Thursday's match against hosts United Arab Emirates.

"I can think about my goals some 10 years later," said the lone surviving member of the 2011 team who lost all three group games in Qatar.

"At the moment, we need to focus. The goals need to come and it just doesn't matter who scores."

Chhetri said the group, which also includes Bahrain, was "tough" but India were confident of matching any of their opponents.

"All the others are more experienced and better than us. But the manner the boys fought, it shows a lot of character. I have said this before, we are a very difficult team to play against," he said.