Sochi , Russia (AFP) — Belgium coach Roberto Martinez hailed his side’s attitude after they overcame a difficult first half to beat Panama 3-0 in their opening World Cup game yesterday.

A superb Dries Mertens strike just after the break and a Romelu Lukaku brace sealed an ultimately comfortable win for the Belgians in the Group G encounter in Sochi, as the Central Americans succumbed to a defeat in their first-ever match at the finals.

In a group also containing England, the performance was not entirely the statement of intent that Martinez’s side would have been hoping to make.

But a victory will do for a team who are, on paper at least, good enough to go far in Russia, especially after heavyweights Germany, Brazil and Argentina all slipped up over the weekend.

“That first goal was going to be essential,” said Martinez. “It is almost a mental blow for one team and it gives you a lot of breathing space for your first game in the tournament, and I thought from that point on we were more ourselves, more in control.”

Belgium are now unbeaten in 20 matches, although the nature of the first-half performance against weak opposition showed that Martinez’s men still have significant progress to make if they are to improve on quarter-final appearances at the past two major tournaments.

“It was our first World Cup game and we wanted it to be perfect,” said the Spaniard, who was also keen to praise the opposition.

“We don’t want to take any credit away from Panama. What they did in the first half, they deserve huge credit, and my players deserve credit for what they did in the second half.”

To be fair to Martinez, the Spaniard had warned on the eve of the game that his side would not have it easy.

Panama lined up with a team of journeymen featuring five 30-somethings. Jaime Penedo in goal is 36, while Blas Perez up front is 37.

But Hernan Dario Gomez’s side competed well in the first period especially, before eventually being undone by the quality at Belgium’s disposal.

“Nobody likes losing, but that was a normal result. I told the players it had been an honourable performance. Our physical condition makes it hard for us against European teams,” said Gomez.

Skipper Eden Hazard pulled the strings when he could, and the Chelsea star was denied by Penedo in the 38th minute with Belgium’s best chance of the first half.

They needed a spark from somewhere, and they got it from Mertens in the 47th minute.

The Napoli man’s cross looking for Lukaku was headed out by Roman Torres and on by Fidel Escobar. But the ball dropped perfectly back to Mertens, whose volley from the right side of the box arced into the far corner.

Michael Murillo was then denied an equaliser for Panama by a fine save from Thibaut Courtois.

But the gulf in class began to tell as Belgium doubled their lead midway through the second half. Hazard found Kevin De Bruyne, and his sumptuous cross with the outside of the right boot was headed in by Lukaku.

With Panama forced to throw more bodies forward, they were punished on the break a quarter of an hour from the end.

This time Hazard released Lukaku, and the Manchester United man beat Penedo to complete the scoring and take him to five goals at major tournaments, as Belgium get up and running.

That is in contrast to some of the other tournament favourites, but Martinez said he was not distracted by anyone else.

“We can’t look at anybody else. Our way of playing depends a lot on our attitude and I really liked the attitude and commitment of my team in a game where you have nothing to win.”