Spain made a superb start to their World Cup finals campaign with a 4-0 demolition of Ukraine, raising hopes that they might finally deliver a long run in the competition.

With the added cutting edge in attack of David Villa and Fernando Torres, Luis Aragones' side easily stretched their unbeaten run to 23 games and put themselves firmly on course for the knockout stages.

However, Arsenal midfielder Cesc Fabregas has warned: "It could be a bit dangerous to think that every game will be like the first one.

"Everyone is now saying that Spain are fantastic, while before they had doubts about us, but there is only one thing in our minds and that is the Tunisia game.

"Often the teams that you think are less strong turn out to the toughest opponents and vice versa. We came here to play against the best sides and we want to finish top of the group."

Veteran coach Aragones has neither injury nor suspension problems to worry about, having all 23 squad members available for the game.

Tunisia coach Roger Lemerre expects a tough afternoon, but the Frenchman believes his side can push their opponents all the way.

He said: "Maybe we have less skill, but more strength. There will be a clash of styles.

"In terms of strength and presence, maybe we can also pose them some problems. If the Spanish impressed in the first game, it was because they all pulled in the same direction and went for the three points.

"But we have to give 100 per cent of what we can, technically, tactically and above all collectively. Maybe the Spaniards will be the first ones to begin to doubt."

However, Lemerre's preparations continue to be blighted by the absence of leading striker Francileudo Santos, who is still struggling with a shin injury.

Brazilian-born Santos, who has scored 18 goals in 28 games for his adopted country, will definitely miss the clash with Spain and is rated as doubtful for the Group H finale against Ukraine.