Atletico Madrid had to settle for a draw with Malaga which leaves them 11 points off top spot, while Real Mallorca claimed a crucial victory in their battle against relegation.
Elsewhere, European hopefuls Real Sociedad and Real Betis shared six goals and Espanyol drew 0-0 with Real Valladolid.
Second-placed Atletico Madrid failed to fully capitalise on Barcelona's loss to Real Madrid as they were held to a goalless draw at Malaga.
Los Rojiblancos could have cut the gap to single figures, following Barca's 2-1 reverse at the Santiago Bernabeu, had they managed to overcome Malaga.
But the fourth-placed hosts proved tricky opposition and just about held their own to claim a point which kept their own Champions League aspirations on track.
Real Mallorca snatched a late 2-1 win at Granada to record their first Primera Division victory in 10 matches.
The hosts took an early lead through Nolito but Alfaro levelled in the 13th minute.
Granada had the greater number of chances throughout the match but a last-gasp headed goal by substitute Tomer Hemed gave the visitors all three points and their first win of 2013.
Dorlan Pabon scored twice as Real Betis held off Real Sociedad's fightback to take a point from a thrilling encounter which ended 3-3.
Jorge Molina gave Betis a half-time lead after Antoine Griezmann's brilliant strike was disallowed at the other end.
Pabon doubled the lead but Sociedad roared back with three goals in 11 minutes from Carlos Vela, Inigo Martinez and Xabi Prieto, the latter with a penalty.
But Pabon's second secured a deserved share of the spoils for Betis, who remain just a point behind Sociedad in seventh.
Espanyol and Real Valladolid played out a dull goalless draw at the Cornella-El Prat in a game where excitement and chances were in short supply.
Valladolid got the point they would have wanted from the clash but Javier Aguirre's side would have left disappointed after previously picking up 16 points from a possible 18 home points since the Mexican replaced Mauricio Pochettino at the helm.
More to follow.
