Spain coach Luis de la Fuente said on Thursday that Belgium would provide his side's sternest test yet in the World Cup quarter-finals, with his team having reached the last eight without conceding a goal.

Among the favourites to lift the trophy, Spain booked their place in the quarter-finals with a 1-0 win over Portugal and have grown into the tournament with a balanced side that is comfortable in possession, solid in defence and boasts enough attacking quality to trouble any opponent.