Barcelona opened up a 12 point lead at the top of La Liga, whilst Deportivo La Coruna moved to within touching distance of fifth placed Celta Vigo and Villarreal drew with Atletico Madrid.
Frank Rijkaard's outrageously talented Barca outfit eased to a 2-0 win over Real Sociedad at Estadio Anoeta thanks to goals from strikers Samuel Eto'o and Henrik Larsson.
The Basque side had a number of chances but Barca's class prevailed and the reigning Liga champions took the lead after just eight minutes.
Larsson had a hint of offside about him as he collected Ronaldinho's cross, but there was nothing suspect about his sumptuous control and finish as he pulled the ball down and stabbed home for his tenth strike in 15 games.
Barca keeper Victor Valdes had to be alert as he produced good saves to deny both Mikel Alonso and Morten Skoubo, and his Sociedad counterpart Alberto was also on fine form as he tipped a Mark van Bommel effort over the crossbar.
The home side were not humbled in the presence of the all-conquering Catalans, and on-loan Liverpool winger Mark Gonzalez was desperately unlucky not to see his bullet of a shot sneak over the line after hitting Valdes when rebounding off the post.
Equally Eto'o could have notched his name on the scoresheet after a clever quick-free kick from Ronaldinho allowed him to spring in behind the Sociedad defence and fire an effort at Alberto.
However the Cameroon star did not have to wait too long for his 20th of the Liga campaign as six minutes after the break he showed his predatory instincts to rattle a shot home after van Bommel had hit the post following an intelligent dummy from Larsson.
Nihat Kahveci began to cause the Barca backline some problems but Rijkaard's men had little difficulty in seeing out the game to extend their lead over Real Madrid and Valencia.
Villarreal moved up to sixth after sharing a 1-1 draw with fellow European hopefuls Atletico Madrid.
The Yellow Submarines took the lead through star striker Diego Forlan after just nine minutes, although their advantage was pegged back when Atletico's own shooting star, Fernando Torres, netted before the hour mark.
On an eventful night for strikers at El Madrigal, Atletico then saw former Chelsea man Mateja Kezman dismissed in the closing stages for two bookable offences.
In the early kick-off Deportivo shrugged off their midweek Copa del Rey defeat by beating Getafe 2-1.
Depor edged in front through star winger Victor on the half hour mark, but tenth placed Getafe drew level through Sergio Pachon on 58 minutes.
However their challenge was compromised when Jaime Gavilan was red carded on 71 minutes and just 60 seconds later Xisco nodded in the winner for Depor.
Villarreal host Atletico Madrid in the late kick-off in a game that could have a profound influence on the scrap for the European places.