Rafael Nadal has said that he was flattered by the emphatic scoreline against Juan Monaco.

The Spaniard, who is aiming for his seventh triumph at Roland Garros, produced some stunning play to win through to the last eight in Paris in straight sets.

However, the 26-year-old said that he has sympathy for his Argentine opponent, who he believes was unlucky to be on the receiving end of a 6-2 6-0 6-0 defeat.

Nadal said that he was happy with his performance but was full of praise for Monaco, who he revealed is one of his best friends on the ATP Tour.

"This result is lopsided," said Nadal. "I shouldn't have this type of score against one of the best players in the world.

"In my opinion, he was unlucky in the first set. That's my feeling, 6-2 was too much. Later, for sure I was very happy the way I played. I feel very, very sorry for him.

"I think he's playing probably the best tennis of his career, but probably not today, especially in the last set. I saw him suffering a little bit on court at the end. He's one of my best friends on tour."

Nadal will now play compatriot Nicolas Almagro in the quarter-finals.