Luis Suarez scored both the goals for Barcelona, both assisted by Lionel Messi.
Spain striker Iago Aspas dealt a fresh blow to Barcelona's La Liga title hopes by striking a late free-kick to snatch a 2-2 draw at home to the Catalans on Saturday as Quique Setien's side twice threw away the lead in a thrilling match.
Luis Suarez headed Barca in front in the 20th minute thanks to a piece of ingenuity from Lionel Messi, who looked certain to fire at goal from a free-kick but instead lofted the ball towards his Uruguayan strike partner.
Russia striker Fedor Smolov equalised for Celta early in the second half before Suarez again combined with Messi to restore Barca's lead in the 67th minute. However, Aspas converted a free kick with two minutes remaining.
The draw put Barca back on top of the table on 69 points but Real Madrid, on 68, can go two points clear at the summit with seven games to go if they beat Espanyol away from home on Sunday.