MADRID (AP) - Barcelona stumbled to a 3-2 home loss against Valencia on Saturday, giving Atletico Madrid a chance to move into sole possession of first place in the Spanish league.
Barcelona's decision not to sign a defender during the January transfer window may have backfired after Valencia took advantage of a lethargic, uninspired effort by its hosts at the Camp Nou, where former Spain coach Luis Aragones - who previously coached the Catalans - was honored after his death on Saturday.
Barcelona led through Alexis Sanchez's eighth-minute goal but Dani Parejo equalized for Valencia before the break.
Pablo Piatti headed Valencia ahead after the restart before Lionel Messi's penalty - and first league goal since September - leveled the game again.
But Barcelona's defense let Sofiane Feghouli burst free into the area to set up Paco Alcacer's 59th-minute winner.
Barcelona played with 10 men from the 78th after Jodi Alba was shown a second yellow card.
The defeat means Atletico can take over sole possession of first for the first time this season if it does not lose at home to Real Sociedad on Sunday, when Real Madrid can also overtake its greatest rival with a victory at fourth-place Athletic Bilbao.
Atletico and Barcelona share 54 points, while Madrid has 53.
Messi set up the opener after slashing a pass across the box beyond the far post where Alexis connected oddly to float it over goalkeeper Diego Alves.
Diego Alves denied Alexis and Dani Alves saw a good shot attempt go wide as Barcelona failed to build on its early momentum. Valencia took control from the 44th when Parejo exploited a turnover inside the Barcelona half to lead a breakout with Feghouli, who returned a pass inside the area for Parejo to score easily.
Valencia went ahead in the 48th when Piatti - who is 1.63 meters (5-foot-3) - held off Dani Alves to jump high and head a looping ball over goalkeeper Victor Valdes.
Valencia was unlucky as Pedro Rodriguez redirected a shot off Ricardo Costa inside the area to set up the spot kick, even though it appeared Costa had no chance of getting out of the way as the ball grazed his shoulder.
Messi slotted home his 10th league goal in the 54th, and first since Sept. 28 against Almeria.
Barcelona's defense was dormant five minutes later as Feghouli moved around three players to the goal line before cutting back to meet Alcacer, who blasted past Valdes for the winner.
Valencia, which was Spain's most active team in the January transfer window but used just one new recruit in striker Eduardo Vargas, snapped a five-game winless run to deal Barcelona its first home league defeat in nearly two years.
Later Saturday, Levante plays Rayo Vallecano, Getafe faces Valladolid, and Sevilla is at Malaga.
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