- Real Madrid coach Jose Mourinho hits back at criticism
- Cristiano Ronaldo scores twice as Real win 4-3 against Sociedad
- Barcelona coach Tito Vilanova returned to the dugout following cancer surgery
- Juventus stunned at home by Sampdoria, Inter lose at Udinese
When it comes to the theater, Jose Mourinho is the man who really does seem to sense that all the world's a stage.
On his return to the Bernabeu following the winter break, Mourinho was cast as villain once again as the home crowd poured forth their ire onto the Portuguese coach.
Forget that Real won this game against Real Sociedad 4-3 and did so after playing with ten men for most of the contest.
It was Mourinho's decision to leave goalkeeper Iker Casillas, a national and Real treasure on the substitute bench, which had irked those in the stands.
The natives are unhappy with Mourinho's management style, not to mention the fact that Real sits 16 points off league leader and great rival Barcelona after just 18 games.
Casillas, who started on the bench, entered the action after just six minutes when fellow goalkeeper Adan was sent off for a professional foul.
The Spain international played the remaining 84 minutes, but Mourinho was still subjected to criticism from the stands.
"Perfect. Let them whistle me before the match and then support the team as they are doing. I think the whistles are for leaving Casillas out and also because we are not achieving our aims in the championship," Mourinho told reporters.
"There are others who didn't applaud and are not happy with his (Casillas') performances. If I am not doing well it is normal that they whistle and it is something you have to live with. I don't want to be a hero independently of my performances."
"I told Adan before the game that the whistles he is likely to hear are for me and not for him but in my opinion there was a lack of respect for him.
"He is a player who has been 16 years at Real Madrid, he was born in Madrid and he didn't deserve that.
"Adan deserves to be happy but I don't know why in Spain that happened. The problem is that the press have turned an attack on Jose Mourinho into a lack of respect for Adan."
While supporters may have been angry at Mourinho, they were at least treated to a thrilling affair with Real Sociedad playing a full part.
Xabi Prieto scored a hat-trick for the visitor, but still couldn't prevent Real from taking all three points.
Two goals from Cristiano Ronaldo and further strikes from Karim Benzema and Sami Khedira sealed the win.
Sociedad also finished the game with ten men after Dani Estrada was shown a second yellow card in the 80th minute.
Elsewhere, Barcelona welcomed coach Tito Vilanova back from cancer surgery with a comfortable 4-0 win over city rival Espanyol.
Vilanova underwent an operation to remove a tumor from his lung after suffering a recurrence of a problem on his parotid gland -- located at the back of his mouth.
"I would like to thank everyone for their support," Vilanova told reporters.
"This club has had a lot of knocks in the last couple of years but I always want to take the positive approach. What has happened to me could have happened to anyone.
"This is not over yet and there will be days that I can take training and others I can't, but I want the media to realize that this illness is mine and it is private."
Pedro Rodriguez hit a double with Xavi Hernandez and Lionel Messi also on target as Barca made it 17 league wins from 18 games.
Atletico Madrid sits 11 points adrift in second following a 1-1 draw at Mallorca, while Celta Vigo eased its relegation worries with a 3-1 win over Real Valladolid.
In Italy, Juventus suffered a shock defeat after going down 2-1 at home to Sampdoria.
Sebastian Giovinco had given Juve a 24th minute lead from the penalty spot, but a classy double from Emanuel Icardi allowed Samporia to snatch all three points.
Juventus sits five points clear at the summit with Lazio in second following its 2-1 win at Cagliari on Saturday.
Juve's defeat will have come as a relief to Inter, which is already nine points off the pace and was beaten 3-0 by Udinese in Sunday's early game.
Antonio di Natale scored twice and Luis Muriel was also on target as Udinese eased to victory.
Napoli crushed Roma 4-1 thanks to a stunning hat-trick from Uruguay international Edinson Cavani.
Elsewhere, AC Milan claimed a 2-1 win over Siena thanks to goals from Bojan and Giampaolo Pazzini, while there were also wins for Chievo, Genoa and Parma.
In the English FA Cup, arguably the most famous domestic knockout competition in world club football, Premier League giant Liverpool was given a scare by fifth tier side Mansfield.
The minnow put up a brave fight before going out 2-1 with Daniel Sturridge and Luis Suarez scoring for Liverpool, which faces third tier Oldham in the next round.
In the day's other tie, Swansea and Arsenal finished level at 2-2 following a frantic second half.
Spain striker Michu gave the home side the lead before goals from Lukas Podolski and Kieran Gibbs appeared to have put Arsenal through.
But Danny Graham popped up with a late equaliser to ensure the teams meet again in a replay.
The winners of the tie will face Gus Poyet's Brighton & Hove Albion in the next round.
Other notable ties in the fourth round will see Premier League champions Manchester City travel to Crystal Palace or Stoke, West Ham or Manchester United host Fulham or Blackpool, while Chelsea will go to minnow Southend or local neighbors Brentford.
Meanwhile, Chelsea midfielder John Obi Mikel insists he will be fit to play for Nigeria at the Africa Cup of Nations, despite missing the club's past three games with a knee injury.
"I'm okay," he told reporters. "I had a knock two weeks ago and was told to rest for some time, but now I am fit and I actually started training two days ago with the Chelsea first team.
"So there should be no fears about any injury. I'm ready for the Nations Cup."
After Lyon's shock defeat to amateur side Epinal, league leader Paris Saint-Germain was given a scare of its very own in the French Cup.
Minnow Arras took PSG all the way to the wire before eventually falling to a 4-3 defeat in a thrilling cup tie.