Bilbao, Spain (SportsNetwork.com) - Real Madrid suffered a major setback in its quest for the La Liga title, dropping points in a 1-0 loss to Athletic Bilbao at San Mames on Saturday.

The visitors were undone by a header from Aritz Aduriz midway through the opening period, a goal that keeps the Galacticos on 61 points and opens the door for Barcelona to move to the summit with a victory over Rayo Vallecano on Sunday.

The two sides traded a few half-chances in the early going of the match, but Bilbao took a shock lead in the 26th minute when Mikel Rico's dangerous cross was turned into the upper corner by a brilliant snap header from Aduriz.

Aduriz came within inches of doubling Athletic's advantage in the 76th minute when he sent a looping header toward goal, but the post came to the aid of Iker Casillas as the attempt skimmed the outside of the woodwork on its way out of play.

Real Madrid also struck the frame with Gareth Bale catching Gorka Iraizoz off his line with a searching long-range effort in the 83rd minute. The ball bounced back into play, but second-half substitute Javier Hernandez failed to convert.

It was the last moment of meaningful action for Madrid as Bilbao closed out the match with all three points intact, lifting the club to 33 points on the season.

Sevilla claimed three points from an enthralling 4-3 victory at Deportivo on Saturday.

Orion Riera handed the hosts the lead after 28 minutes, but a brace from Vitolo put Sevilla in front by the 52-minute mark.

Kevin Gameiro made it three for Sevilla by converting a penalty in the 65th, but Riera pulled one back for Deportivo seven minutes later.

An own goal from Sidnei restored Sevilla's two-goal advantage in the 83rd minute, a goal that proved to be the winner after Lucas converted a penalty for Deportivo on the stroke of full time.

Also on Saturday, Victor Romero Rodriguez provided the lone goal in Elche's 1-0 defeat of Almeria while an own goal from Ignacio Camacho gifted Granada a 1-0 victory over Malaga.