Deportivo Coruna knocked Real Madrid off the top of the Spanish first division on Saturday after they claimed a 2-0 win over Malaga while the former leaders were held to a goalless draw at lowly Recreativo Huelva.
Deportivo now top the table for the first time this season with 66 points, while Real drop to second a point behind.
Third-placed Real Sociedad also have a chance of overhauling Real in the standings if they win their match at Real Mallorca on Sunday.
Deportivo's 40-year-old defender Donato, the oldest player in the league, grabbed the opener with a fine glancing header in the 13th minute after a near post corner from Victor.
Javier Irureta's side suffered a few late scares as Malaga threw men forward in search of an equaliser, but midfielder Lionel Scaloni confirmed victory when he scored on a counter-attack in injury time.
Real Madrid have frittered away a four-point cushion at the top of the table in the space of just two games.
With the injured Ronaldo, Raul, Luis Figo and Zinedine Zidane remaining in Madrid, Real lacked fluency at the Nuevo Colombino.
Recreativo centre forward Raul Molina proved an instant menace to the Real defence, shooting wide after just 25 seconds and getting close to touching in an Emilio Viqueira free kick five minutes later.
He also managed to get the ball in the net but his goal was ruled out for offside.
Real then had a brief spell in control as Roberto Carlos made several runs on the left and striker Fernando Morientes threatened on the edge of the area.
Real striker Tote then had a spectacular goal-bound shot blocked by defender Mariano Pernia on 15 minutes and Morientes skied over soon after, but Recre fought back and came within a whisker of snatching the lead just before halftime.
Molina raced on to a long pass with just Iker Casillas to beat, but the Real goalkeeper blocked the shot with his feet.
CASILLAS RESCUE
Casillas came to the rescue once more after the restart, diving to his left to turn a sharp shot from Mario Bermejo past the post and blocking another Molina effort soon after.
While Recre had little problem keeping Vicente del Bosque's side at bay the draw was not enough to keep them out of the drop zone.
Earlier on Saturday, strugglers Alaves claimed their first win in 11 outings when they edged to a 1-0 victory over Atletico Madrid at the Calderon thanks to a breakaway goal from substitute Adrian Ilie 10 minutes into the second half.
But with Osasuna claiming a 0-0 draw at Espanyol the Basque side remain in the relegation zone, level on points with Recreativo.
The defeat for Atletico, whose coach Luis Aragones announced this week that he would quit at the end of the season, effectively put an end to their hopes of a gaining a place in Europe.
