Portugal defender Pepe has given a glowing tribute to international and club team-mate Cristiano Ronaldo after his goal booked the nation into the Euro 2012 semi-finals, while admitting that they faced a tough task to make it to the final.

The Real Madrid star's header led the Portugal team past Czech Republic in Thursday's quarter-final, holding on to win 1-0. Their reward is a clash against either Spain or France in the penultimate stage, with the identity of the next opponent to be revealed on Saturday evening.

Pepe praised the forward for keeping a cool head during some less than friendly receptions from opposing fans, and stated that his calmness under pressure marked him out as a special talent in world football.

"The more you talk about Cristiano Ronaldo, the stronger he gets. He is a player from another world. To him, being the best in the world means little. He is outstanding," the centre-back told RTP.

"On the field of play, I look at him and I think he is from a different planet. He outdoes himself in every game he plays."

Pepe went on to admit that it would be a tough task for Portugal to win their first ever title at Euro 2012, but stated that the squad were still hoping to make history.

He added: "It will be hard to win the Euros. It is a dream we have, but we will have a very difficult game in the semi-finals.

"Neither Spain, nor France, are easy. One of them is the world champion, while France are playing well again and have great players. Their team is more balanced now. All we have to do is get ready, to win the match."

Born in the Brazilian city of Maceio, Pepe opted to play for the Portuguese national team and made his international debut in 2007, also appearing at Euro 2008.