(Reuters) - Ange Postecoglou was left to rue a series of missed chances after Celtic slipped to a 4-3 Europa League defeat to Real Betis on Thursday as he became the first Australian to coach in the group stages of a major European club competition.

Celtic took a two-goal lead in Spain but Betis hit back with four goals in 21 minutes before Anthony Ralston's 87th minute effort gave the Glasgow side hope late on.