- La Liga's top two sides play out 0-0 draw as season reaches halfway point
- Both Barca and Atletico have 50 points from 19 games with Barca top on goal difference
- Real Madrid can close gap with leaders to three points with win at Espanyol on Sunday
Barcelona and Atletico Madrid remain virtually inseparable in La Liga after Saturday night's top-of-the-table clash at the Vicente Calderon Stadium ended in a 0-0 draw.
As the season reaches its halfway point, both the Catalans and the Red and Whites have 50 points, with only Barcelona's superior goal difference separating the two teams.
The first half was a tight affair with both teams careful not to give away an early advantage in what could be a decisive game in the fight for the title.
Despite scoring twice in his comeback match against Getafe in midweek, Lionel Messi once again started on the bench but came on for the injured Andres Iniesta at halftime.
The Argentine's introduction gave Barca more bite in attack but still Atletico held firm.
Neymar's arrival in the 66th minute -- the Brazilian striker also started on the bench after missing the match against Getafe with a bout of gastroenteritis -- added another string to Barcelona's attacking bow but a goal didn't materialize.
Messi, who will be hoping to retain FIFA's Ballon D'Or when the winner is announced on Monday, passed and probed but couldn't find a way through. His best chance came nine minutes from the end but the 26-year-old was denied by a fine save from Atletico's Belgian keeper Thibaut Courtois.
Diego Simeone's side had their moments too with Diego Costa narrowly missing out at the far post when Brazilian defender Miranda flicked on Koke's corner kick in the 28th minute.
Turkish midfielder Arda Turan, who provided much of the Atletico's creative spark, also saw a chance go begging with 12 minutes to go -- his mistimed volley easily scooped up by Barcelona's keeper Victor Valdes.
Both teams are now six points ahead of third place Real Madrid, but Carlo Ancelotti's side will reduce their arrears to three if they beat Espanyol on Sunday.
In Saturday's other La Liga fixtures, fouth-placed Athletic Bilbao romped to a 6-1 victory over Almeria while Valencia's stuttering season continued as they went down 2-1 at Celta Vigo.
Two matches were played in Serie A on Saturday with Parma climbing to seventh after running out 3-0 winners at second-from-bottom Livorno while the match between Bologna and Lazio ending goalless.
League leaders Juventus travel to Cagliari on Sunday with second place Roma entertaining Genoa.
Fifth place Hellas Verona host third place Napoli and Fiorentina, who are currently fourth, travel to Torino.
Inter play Chievo Verona at the San Siro on Monday evening.