The European champions had a second-half David Villa strike to thank for their victory on Tuesday and Del Bosque was happy with what he saw. "The match was extremely intense," he said. "It was quite even in the first half, but we always controlled the game and in the second half we were better than them. We had greater depth but it was a difficult game and our rivals were extremely solid."
Villa pounced in the 63rd minute, chipping a rebound over goalkeeper Eduardo after his first shot was saved to keep his team on track for their first ever FIFA World Cup™ title.
If they beat Paraguay on Saturday then Argentina or Germany await them in the semi-finals, although Del Bosque is only looking ahead one match at a time. "We shall not underestimate Paraguay and prepare for them with great respect," he said of a team who won a dramatic penalty shoot-out 5-3 against Japan after their last-16 match in Pretoria finished scoreless.
"They have very good defenders but also attackers. We must be fully focused to win that match. We know how difficult it is to be victorious, we can't take anything for granted. We must be hugely respectful of our next opponents."
Barcelona's Villa, who now has four goals in South Africa, refused to see Spain as clear favourites against the Paraguayans, who are in their first ever FIFA World Cup quarter-final. "I am very happy tonight, although there are two favourites for the quarters. However, I am confident we can come through," he said.