Lionel Messi and Cristiano Ronaldo started 2013 in the same vein as last year, finding the back of the net in contrasting victories for Barcelona and Real Madrid in the La Liga.
Messi scored his goal from the penalty spot, with a brace from Pedro and one more from Xavi earning the league leaders a comfortable victory over city rivals Espanyol.
Ten-man Real needed two Ronaldo strikes to earn themselves a nervy 4-3 win over Real Sociedad, with the other goals coming from Karim Benzema and Sami Khedira.
Barcelona pulled further clear of the chasing pack, following the win, with Atletico Madrid managing only a 1-1 draw at Mallorca - Diego Simeone's men clearly struggling to find the target without their talisman Radamel Falcao, who was suspended.
The results on the night meant, Real Madrid stayed 16 points behind their biggest rivals, with Barca extending their advantage over Atletico to 11 points - and with it virtually sealing the title, if there was ever any real doubt, with nearly half the season remaining.
At the Camp Nou, it was all about Barca manager Tito Vilanova, making a remarkable return from cancer for the second time, and finding himself back in the dugout just two weeks after a throat operation.
"I feel very supported and protected by the club," Vilanova told reporters after the game. "I want to thank my staff and the players. This group has had too many close calls and I think it will help us, this situation keeps our feet on the ground because we are no different from anyone else.
"This (the fight against cancer) is not over and even though I have a public job, the illness is mine, it's private."
Xavi opened the scoring in the 10th minute, taking a pass from Ballon d'Or nominee Andres Iniesta, before side-footing it into the back of the net. Pedro made it 2-0 five minutes later, slamming home off a Cesc Fabregas pass.
Pedro completed his brace in the 27th minute, before Fabregas earned Barca a penalty two minutes later, which was duly dispatched by Messi, the favorite to win the world player of the year award Monday.
At the Bernabeu, there was drama right from the beginning, with the home crowd making their feelings clear when goalkeeper Adan's name was read out, instead of the fan favorite Iker Casillas.
Benzema then gave Real the lead after just 90 seconds, but Jose Mourinho's unpopular decision to field Adan backfired when the young keeper, trying to make up for a poor pass, brought down former Arsenal striker Carlos Vela inside the box.
The referee showed the custodian a straight red card, and awarded a penalty to Sociedad.
"It looked like it was a penalty but we had one or two players between him and the goalline," Mourinho told reporters.
"To me, if it was in a different stadium it would only have been a yellow card."
Casillas was brought on amid much cheer, but the Spanish international could do nothing to stop Xabi Prieto from making it 1-1.
Khedira regained the lead for Real, but Prieto was again on hand to equalize just before the break. Real, despite playing with only ten men right from the fifth minute, looked the more dangerous and got a deserved goal through Ronaldo, slotting it past the Sociedad goalkeeper off a pass from Benzema.
The Portuguese forward then made it 4-2 with a freekick, before Prieto completed his hat-trick to bring the score back to 4-3. However, Real held on for a much-needed win, with Sociedad defender Daniel Estrada also receiving his matching orders late on for a second bookable offense.
Results: Barcelona 4-0 Espanyol; Real Madrid 4-3 Real Sociedad; Mallorca 1-1 Atletico Madrid; Levante 3-1 Athletic Bilbao; Granada 1-2 Valencia; Deportivo 1-0 Malaga; Sevilla 1-0 Osasuna; Celta Vigo 3-1 Valladolid; Real Zaragoza 1-2 Real Betis.