Barcelona lost the lead of Spain's Primera Liga after their 1-1 draw with Deportivo La Coruna on Saturday was followed by a win by Sevilla on Sunday.
Kanoute (left) notched his eighth goal of the season on Saturday
Sevilla beat Osasuna 2-0 thanks to goals from Frederic Kanoute and Adriano Correira to leave Barca a point adrift.
Barcelona drew at the Riazor on Saturday four days after a 2-2 draw with Chelsea left them fighting to stay in the Champions League.
Real Madrid missed a chance to go top with a 2-1 home defeat by Celta Vigo.
It was the first defeat at the Bernabeu suffered by Real coach Fabio Capello in either of his spells at the club.
Celta took the lead in the 35th minute with their first attack when Fabian Canobbio crossed for Nene to score.
Emerson equalised for Real when he headed in Raul's corner, but Jorge got the winner eight minutes from time after a mistake from Jose Reyes.
Ronaldo made his first start of the season for Real and David Beckham was again used as a second-half substitute.
Ronaldo, dubbed "too fat" by Capello last week, created a host of chances but failed to score.
The result meant Sevilla stayed top after they displaced Barcelona on Saturday.
Their first goal against Osasuna was a Kanoute penalty and he was involved in the second as well, feeding Brazilian midfielder Adriano at the end of a swift counter-attack.
But coach Juande Ramos said his side's leading the league was "an oddity".
On Saturday in La Coruna, Ronaldinho's penalty gave Barcelona the lead after a foul on Javier Saviola.
Antonio Juan Rodriguez equalised when he knocked in a penalty rebound after Victor Valdes had saved Fabian Estoyanoff's spot-kick.