Barcelona kicked nine points clear at the top of La Liga after a 3-1 win at Real Valladolid while Real Madrid lost on Saturday.
With Barcelona manager Tito Vilanova suffering a relapse of throat cancer this week, his players had no shortage of motivation as they travelled to Estadio Municipal Jose Zorrilla.
And although they took a while to get going, Xavi’s goal on 43 minutes gave Barca the lead heading into the break.
Argentine forward Lionel Messi bagged his 91st goal of the calendar year on the hour-mark and although Javi Guerra’s 89th-minute effort gave the winners a slight scare, it only lasted a matter of minutes.
Substitute Tello was on hand to seal the result in second half stoppage time as Barcelona extended their lead on the second-placed Atletico Madrid.
And Barca would have been delighted with Real Madrid’s 3-2 loss at Malaga which leaves last season’s champions a whopping 16 points off the pace.
After a goalless first half, Isco’s 49th-minute opener for Malaga stung their opponents into gear and they responded on 66 minutes thanks to a Sergio Sanchez own goal.
But a quick-fired double from Malaga’s Paraguayan striker Roque Santa Cruz had more than 27,000 fans in Malaga delighted and although Karim Benzema pulled a late goal back, Jose Mourinho’s men suffered another disappointing defeat.
Malaga – who sit fourth on the table – are now just two points behind Real Madrid.
Other results saw Real Mallorca climb out of the relegation zone with a 2-1 win at fifth-placed Real Betis.
Benat put Betis in front after just six minutes but Victor and Javi Marquez responded for the strugglers who snapped a 14-match winless streak with the surprise result.
Mainz and Dani Benitez netted for Granada in a 2-1 win at Osasuna while Athletic Bilbao and Real Zaragoza played out a goalless draw.