Colombia coach Jose Pekerman has told his players they must keep their feet on the ground and stay focused after their impressive start at the World Cup.

The South Americans, making their first World Cup appearance since 1998, beat Greece 3-0 in their Group C opener in Belo Horizonte.

Goals from Pablo Armero, Teofilo Gutierrez and James Rodriguez handed Colombia a perfect start in Brazil.

"We are very happy to have taken this win," Pekerman said. "It was a good debut for my players who had never played at a World Cup.

"But this is just the first game and we haven't achieved anything yet.

"Our aim is to have a good World Cup and we've had a good start."

Ivory Coast also won their Group C game against Japan, 2-1.

The Africans are Colombia's next opponents at the Nacional Stadium in Brasilia on Thursday.

"Ivory Coast is one of the strongest African teams," Pekerman said. "They have already played in World Cups and have players that have a lot of experience.

"Besides the important players that they have, the fact that they have played at big competitions gives them that necessary calmness to know what is at stake.

"We will have to show the same focus that we had against Greece and try to recover the players as soon as possible considering the intensity of the game against Greece."

Rodriguez, who plays his club football at Monaco, thanked the Colombian fans.

The South Americans had the majority of the fans at the Estadio Mineirao in Saturday's match.

"The atmosphere was just incredible," Rodriguez said. "It felt as though we were playing home in Barranquilla."

The 22-year-old playmaker scored Colombia's third goal in stoppage time.

"It's a dream come true to score at a World Cup," he said. "I'm delighted but the most important thing is that we won and we are on the right path.

"This is only the beginning and all our fans need to be calm but have faith."

Greece are looking ahead to Thursday's clash against Japan at the Estadio das Dunas in Natal.

The Greeks felt they had played better than the final score suggested.

"Against Colombia, we should have done better in the finishing, I don't think we deserved a 3-0 defeat," Greece goalkeeper Orestis Karnezis said. "But unfortunately that's football.

"There are three games in the group and we only lost one.

"For us it's a big success to be here, but we want to win too."

Greece coach Fernando Santos says his players must look ahead to the game against the Blue Samurai and forget the setback.

"You can't make excuses when you lose 3-0," the Portuguese said. "We had good spells of play and all we can do now is look at the next matches."