The hosts took just two minutes to take the lead through Ruben Castro's penalty, but the visitors equalised shortly before the break and will probably feel they deserved the win
The hosts had taken the lead after just two minutes when Ruben Castro fired home from the spot after Salva Sevilla was felled by Gorka Iraizoz, but Aritz Aduriz equalised shortly before the interval and Marcelo Bielsa's side can consider themselves unlucky not to have claimed all three points in Andalusia.
Betis went into the encounter in high spirits after their 2-0 win over Levante, and they wasted no time in making their mark against an inconsistent Bilbao side. Iraizoz inexplicably rushed from goal and took out Salva Sevilla, allowing Ruben Castro to fire high into the top corner from the penalty spot.
Bilbao began to grow into the match and Adrian made his first impressive save of the night when he parried Ander Herrera's stinging drive from the edge of the area, before Iker Muniain's clever run and shot was blocked by Marco Amaya.
Shortly before the break, the visitors found themselves on level terms, as the excellent Herrera picked out Aritz Aduriz with a superb pass, allowing the striker to lift the ball over the on-rushing Adrian and into the net.
Bilbao started the second half as impressively as they finished the first, but Betis carved out the first meaningful chance of the second phase, when Amaya somehow contrived to send his effort wide when unmarked in the area shortly before the hour mark.
The visitors controlled most of the half and Betis had to rely on their keeper to keep scores level as the match wore on. First, Adrian parried a bullet header from Aduriz, before Susaeta skipped into the area only to be denied by the 26-year-old.
But he saved his best until last: in injury time, Ibai Gomez's cross was turned goalwards by Oscar de Marcos, and Adrian showed incredibly agility to claw the ball away from goal and safeguard his side's share of the spoils.
The result leaves Betis in fourth place, while Bilbao climb above Real Zaragoza into 13th.