Pedro opened the scoring after Xavi intercepted
Barca remains on course for a club record 100 points should it win its remaining two games, away to city rival Espanyol and at home to Malaga.
At the other end of the table, Deportivo La Coruna beat Espanyol 2-0 to move out of the relegation zone above Real Zaragoza, which lost 2-1 at home to Athletic Bilbao.
Depor took the lead through a wonderful goal by
Real Zaragoza led through Helder Postiga's 15th-minute header but was pegged back in the final 10 minutes,
Rayo Vallecano survived a late fightback from Levante to take all three points at the Ciutat Valencia stadium with a 3-2 win and move up to eighth in the table.
Top scorer Piti gave Paco Jemez's side a first-half lead which was cancelled out by
Piti struck again, this time from the penalty spot, to increase Rayo's advantage but