Celta Vigo and Real and Betis head in to half time level after neither side could find the back of the net in the opening 45 minutes.
Real Betis were strong for much of the first half, with a series of chances forcing Javi Varas to make saves.
Ruben Castro had a thunderous strike from outside the box saved, before setting up Joel Campbell for a shot from the same distance, which was also stopped by the Celta keeper.
Juan Carlos also looked lively on the ball for the visitors, with an initial effort blocked by the Betis defenders, before he fired the rebound over the crossbar.
The home side saw more of the ball towards the end of the half, Iago Aspas having a shot blocked before Park Chu-Young forced a save from Betis.