Madrid's championship challenge suffered a major blow last Saturday when they slipped to their first defeat in nine league matches after going down 2-1 at Racing Santander.

That loss, combined with Barcelona's last-gasp winner over Real Mallorca, means Madrid could find themselves eight points adrift of the leaders if results go against them this weekend.

And with only seven games remaining after that, it could spell the end for the Spanish giants' hopes of winning their first major trophy since 2003.

Barca face a tricky trip to Villarreal on Sunday, but it is Madrid who have the acid test as they welcome a Valencia side in buoyant mood after downing second-placed Sevilla 2-0 last weekend.

"We have to win, always. Saturday's match is against one of our greatest rivals who are just below us in the table," said Madrid centre-back Fabio Cannavaro.

"We can only think about Real Madrid, not other teams or numbers. We have eight games left, and we have to play well and win. We can do it."

Madrid could welcome back David Beckham for Saturday's match with the former England captain making good progress on the knee injury that has kept him out since the start of March.

Sevilla will look to put that defeat to Valencia behind them when they host lowly Athletic Bilbao on Sunday.

Athletic's proud record of never having been relegated from the top flight looked in serious doubt a few weeks ago but back-to-back wins over Valencia and Espanyol has seen them climb up to 16th spot.

The fight to avoid the drop looks certain to go right to the wire though with a whole host of clubs still not safe.

Bottom two Gimnastic Tarragona and Real Sociedad are both six points adrift of safety and looking increasingly doomed, but above them only four points separate Levante, Celta Vigo, Athletic and Real Betis.

Levante, who currently occupy the third relegation spot, are at home to Getafe, while Betis are at Espanyol.

Celta, who beat local rivals Deportivo La Coruna 1-0 last weekend to move out of the drop zone and give new coach Hristo Stoichkov a winning start, face arguably the toughest match as they go to fifth-placed Real Zaragoza.

Racing Santander will look to continue their remarkable rise up the Primera Liga table when they go to the team immediately below them in the standings, eighth-placed Recreativo Huelva.

Racing have lost just one of their last 13 league matches and their win over Madrid means they are now just three points behind Zaragoza.

"We have high expectations for our next league game because they are a direct rival in our bid to get a UEFA Cup spot," said Racing captain Pablo Pinillos.

"I am sure that at the start of the season nobody thought a game between Recreativo-Racing would be between two teams aspiring to European competition."

In the other matches, Sociedad are at home to Atletico Madrid, Nastic go to Real Mallorca, while Depor host UEFA Cup semi-finalists Osasuna.