Barcelona are now eight points clear of second-placed Real Madrid after victory over Villarreal.
With Real Madrid having lost at home to Sporting Gijon earlier in the day, ending Jose Mourinho's nine-year unbeaten home run in the league in the process, Barca knew a win at El Madrigal would put them on the brink of a third successive title.
An eight-point advantage over Madrid was the prize on offer and, after a sluggish opening hour, Pep Guardiola's men finally found a way to take it as Gerard Pique netted the only goal.
Yellow Submarine striker Giuseppe Rossi, a reported transfer target for Barca, was outstanding during the 90 minutes and appeared to be taking the visitors on by himself.
