Barcelona fly as Real, Milan feel heat
Fellow former European champions AC Milan were also under pressure as they saw their lead in Italy pegged at four points.
Elsewhere in Europe, Borussia Dortmund are comfortably on course for a first German title since 2002 as they opened a 12-point lead while Lille, without a French championship since 1954, kept one point ahead of the chasing pack.
Barcelona swept past Malaga 4-1 while Real Madrid were held to a 1-1 draw at bottom side Almeria.
Andres Iniesta scored the opening goal for Barcelona before World Player of the Year Lionel Messi set up David Villa for the first of his two goals. Pedro Rodriguez added the other goal.
Barcelona reached the halfway stage of the season with 52 points from 19 matches having hit 61 goals while conceding just 11.
Real are on 48 points with Villarreal back on 39 points in the race for Champions League places.
"It is ridiculous to talk about a four-point gap at this stage of the season as it is nothing. There is a long way to go and we can drop points," said Barcelona coach Pep Guardiola.
Esteban Granero rescued a point in the 77th minute for misfiring Real against Almeria who had broken the deadlock through Jose Ulloa.
"We dropped two points but looking at the first half of the season as a whole then we have done well," said Real coach Jose Mourinho.
In Italy, AC Milan were held to a 1-1 draw at Lecce as three of their title rivals bagged late winners to close in on the leaders.
Zlatan Ibrahimovic scored a wonder goal to give Milan the lead only for Uruguayan Ruben Olivera to snatch a share of the spoils.
Milan's lead at the top was pegged at four points from Napoli, who were held to a goalless draw by Fiorentina, and Lazio who enjoyed a late winner against Sampdoria.
Milan coach Massimiliano Allegri said: "We've still got a four-point lead, there's a long way to go but after this draw we need to be calm because the players are in good shape."
One of the biggest threats to Milan is coming from champions Inter who are nine points back after their 4-1 win over Bologna on Saturday, but have two games in hand.
Dortmund blitzed Leverkusen 3-1 with three goals in six minutes as Jurgen Klopp's young side showed no sign of releasing their grip at the top of the German first division.
Goals by Mario Goetze and Kevin Grosskreutz (2) sealed the win.
French international striker Andre-Pierre Gignac finally justified his 18-million-euro transfer fee when he scored his first home league goal for French champions Marseille in a 2-1 victory over Bordeaux.
It was only Gignac's second league strike of the season - his first was at St Etienne in October - although he had hit a Champions League hat-trick against Zilina at the Stade Velodrome.
The win put Didier Deschamps' side into fifth place in the table, three points behind Lille who kept up their unlikely charge for a first French title in over half a century when African strike pair Moussa Sow and Gervinho scored in a 2-0 win at Nice.
In Portugal, FC Porto beat Naval 3-1 to stay eight points ahead of Benfica who edged struggling Academica Coimbra 1-0.