A much-changed Barcelona side were held at Celta Vigo as Ernesto Valverde rested key players before Saturday's Copa del Rey final against Sevilla.
Lionel Messi and Luis Suarez both started on the bench in Tuesday's match and Gerard Pique and Andreas Iniesta were rested, but Barca went ahead through Ousmane Dembele.
Jonny's tap-in levelled the game but Paco Alcacer fired Barca ahead again.
Sergi Roberto was then set off for a pull on Iago Aspas, who equalised via a fortunate deflection late on, according to a BBC report.
Paulinho also hit the post for the La Liga leaders on what was a frustrating night for Valverde's side.
Barca nevertheless extended their unbeaten run to 40 matches and move 12 points ahead of second-placed Atletico Madrid, who have a game in hand