Real Betis failed to put pressure on La Liga's top three with a 0-0 draw at Celta Vigo on Sunday.
Manuel Pellegrini's side, fourth, are a point behind third-place Real Madrid before they visit Barcelona in the Clasico later on Sunday.
Betis had chances to win the game, with Nelson Deossa hitting the crossbar early in the second half and striker Troy Parrott dragging wide in stoppage time.
"The ball didn't want to go in," Betis goalkeeper Alvaro Valles told DAZN, while admitting "the draw was fair". The point leaves Celta provisionally ninth.
Madrid trail leaders Barcelona by six points before the Clasico, with Atletico Madrid second, two points behind the leaders, after a 1-0 win over Deportivo La Coruna on Saturday.
