Atletico Madrid needed a second-half goal from midfielder Koke to earn a 1-0 win at Malaga on Saturday, becoming the overnight leader of La Liga as they resumed following the winter break.
Atletico built a provisional three-point advantage over Barcelona before the defending champions host Elche on Sunday. Barcelona then visits Atletico in the following round.
Atletico dominated possession but were held in check by Malaga's five-man defense until manager Diego Simeone sent on forwards Adrian Lopez and Cristian Rodriguez to join Diego Costa and David Villa up front for the final half-hour.
Diego Costa failed to add to his league-leading 19 goals, but the striker turned playmaker to unlock the hosts' stingy defense in the 70th minute.
He slipped the ball to Adrian, whose rebound off goalkeeper Willy Caballero fell for Koke arriving late to rifle through the crowded area and into the back of the net to claim the winner.
Atletico moved eight points clear of third-place Real Madrid before they host Celta Vigo on Monday.
Also Sunday, Valencia's new manager, Juan Antonio Pizzi, debuted with a 2-0 victory at home over crosstown rival Levante.
Pizzi replaced the fired Miroslav Djukic over the two-week league break, and Valencia responded with a convincing win in the city derby against Levante at their Mestalla Stadium.
After Pablo Piatti drilled in a clearance to put Valencia in front three minutes before halftime, forward Sofiane Feghouli dribbled through the defense and chipped the ball home via the crossbar in the 73rd minute to put the result beyond doubt.
Pizzi will face a tough second test on Tuesday when Valencia host Atletico in the Copa del Rey.
Almeria routed visiting Granada 3-0 to climb four points clear of the relegation zone.
Forward Aleix Vidal led the way by crossing for Sebastian Dubarbier's opener and adding a goal of his own after Verza converted a penalty.
Real Betis remained bottom of the table after a drab 0-0 draw at Valladolid. The draw gave the Seville-based side their second point away from home this season.
Information from The Associated Press was used in this report.