None of the top three Italian Serie A sides managed to win while in France, where the freezing weather disrupted fixtures, Paris St Germain remained three points clear of Montpellier after both teams won.
Leaders Real Madrid maintained their seven-point advantage over chasing Barcelona when Sergio Ramos nodded the only goal in a 1-0 win at city rivals Getafe on a bitterly cold Saturday night in the Spanish capital.
At an equally-chilly Nou Camp in the late kickoff, the brilliance of Lionel Messi lifted a Barca side featuring several youngsters from the B team to a 2-1 win against Real Sociedad, their 10th success in 11 home games this season.
Messi sent pacy 20-year-old Tello clear to open the scoring in the ninth minute and the Argentine World Player of the Year added a second in the 72nd when he hooked in a Daniel Alves cross. Substitute Carlos Vela pulled a goal back for Sociedad two minutes later.
Real, who have won six games on the trot since losing 3-1 at home to Barca in December, have 55 points from 21 matches, with Barca on 48.
Third-placed Valencia missed a chance to extend their advantage over fourth-placed Levante and slipped 11 points behind Barca when they were held to a scrappy 0-0 draw at Atletico Madrid on Sunday.
Manchester City ended the weekend with a two-point lead over title rivals Manchester United after a 3-0 win against Fulham as United fought back from 3-0 down to claim a stirring 3-3 draw at Chelsea on Sunday.
City responded to a midweek defeat at Everton with Sergio Aguero and Edin Dzeko both on target to move Roberto Mancini's side to 57 points from 24 games.
United had the chance to move level at the top in snowy London 24 hours later but had to come back from 3-0 down to grab a point at Stamford Bridge. Wayne Rooney converted two penalties and Javier Hernandez headed the equalizer after a Jonny Evans own goal, a Juan Mata volley and Davis Luiz header had put fourth-placed Chelsea in control.
Newcastle remain in fifth place with 42 points, a point behind Chelsea, after debutant Papiss Cisse scored a late winner in a 2-1 defeat of Aston Villa. Arsenal are sixth (40) after Robin van Persie scored a hat-trick in a 7-1 rout of Blackburn.
Third-placed Tottenham face Liverpool on Monday.
Zlatan Ibrahimovic was sent off for a slap as AC Milan were held to a 0-0 draw by Napoli but the damamge was limited by leaders Juventus also only managing a goalless home stalemate against Siena.
Fabio Borini struck a brace to help AS Roma to a 4-0 home thrashing of Inter Milan and former coach Claudio Ranieri in a match orignially scheduled for Saturday but put back to Sunday because of the heavy snow which has hit Italy.
Third-placed Udinese went down 3-2 at Fiorentina with Stefan Jovetic netting brace while Lazio, who are fourth, also lost 3-2 at Genoa in another cracking game where Bosko Jankovic scored twice for the hosts.
Champions Borussia Dortmund opened a two-point lead at the top of the Bundesliga following their 2-0 win at Nuremberg with goals from goal from captain Sebastian Kehl and Paraguay international Lucas Barrios.
Rivals Bayern Munich had to settle for a 1-1 draw at Hamburg SV and were lucky to escape with a point as they have yet to peak since the Bundesliga restart, having won only one of three league games this year.
Schalke 04 also joined Bayern on 41 points, after a 1-1 draw at Mainz 05 while the fourth title contender, Borussia Moenchegladbach drew 0-0 at VfL Wolfsburg to remain in fourth place on 40 points.
A Nene double helped Paris St Germain claim a 3-1 comeback win against visitors Evian Thonon Gaillard and maintain their three-point lead at the top on Saturday.
Second-placed Montpellier beat Stade Brest 1-0, also on Saturday, to keep the pace. Champions Lille stayed third 10 points adrift after their game at Sochaux was postponed because of a frozen pitch. Two other matches were canceled as temperatures dropped below zero in France.
Fifth-placed Olympique Marseille and Olympique Lyon, who are fourth, lost ground after a 2-2 draw at the Stade Velodrome on Sunday. Marseille trail PSG by 11 points and Lyon by 10.
PSV Eindhoven stretched their lead to three points despite a 1-1 draw at Heracles Almelo as Twente Enschede and AZ Alkmaar had their matches postponed due to the freezing weather.
Ajax Amsterdam suffered a 2-0 home defeat against Utrecht, with Edouard Duplan scoring a double, as they slipped to sixth, eight points behind PSV.
Heerenveen and Feyenoord won their matches against Roda JC Kerkrade and NEC Nijmegen respectively to close to five points from the top.
Kevin Mirallas scored his 12th goal of the season as Olympiakos Pireaus clinched an impressive 2-0 away win over PAOK Salonica on Sunday to move to within two points of league leaders Panathinaikos.
Panathinaikos lost 1-0 to Levadiakos. AEK Athens moved third with a 1-0 home victory against Panionios.
