Barcelona moved 12 points clear on top of the La Liga table after they thumped Getafe 6-1 and Atletico Madrid lost on Sunday.
The Catalan giants made a terrific start to their fixture at the Nou Camp, taking the lead after just six minutes thanks to an assured finish from Alexis Sanchez.
The Chilean made the most of a splendid diagonal pass from Andres Iniesta, taking a smart touch before tucking the ball past Getafe goalkeeper Jordi Cordina.
Just seven minutes later the lead was doubled, with Iniesta's lob over the defence finding Thiago Alcantara, who cleverly laid the ball off for Lionel Messi.
The Argentine lost his footing as he shot but it was still good enough to sneak into the back of the net as he scored for the 13th La Liga match in a row.
Messi was only denied a second on the half-hour by the woodwork but David Villa - enjoying a rare start for Barcelona - killed the game off with his side's third on 58 minutes, making the most of a perfect Jordi Alba pass.
Substitute Tello was lively for Barcelona and added a fourth with a stunning strike from the edge of the area and although Getafe pulled back a consolation through Alvaro, Iniesta and Gerard Pique scored late to give the Catalans a convincing victory.
Their win, in conjunction with Atletico's 2-1 loss to Rayo Vallecano, has virtually ended the title race.
The hosts started well thanks to a goal from Alhassane Bangoura after just three minutes.
Paco Jemez's side added another on 33 minutes with Bangoura involved again, setting up Leo Baptistao for the game's second goal.
Atletico had 14 shots on goal to their opponents' five, but their goal came too late to make a real impact on the match.
Colombian Radamel Falcao scored the consolation, but his effort in the fifth minute of stoppage time was in vain as Rayo Vallecano celebrated a win that took them to sixth on the table.
Espanyol extended their unbeaten streak in La Liga to five matches - four of which have been wins - with a 4-0 trouncing of Athletic Bilbao.
Hector Moreno gave Espanyol the lead after 28 minutes before Victor Sanchez and Christian Stuani scored within 60 seconds of each other early in the second half.
Verdu wrapped up the rout with a goal 15 minutes from time as the visitors celebrated a superb win.
Athletic Bilbao have now won just one of their past seven La Liga fixtures.
The day's other match saw Real Sociedad win 2-1 at Real Zaragoza thanks to strikes from Antoine Griezmann and Imanol Agirretxe.