Aston Villa's hopes of reaching the Europa Conference League final were hit by a chaotic semi-final first-leg defeat to Olympiacos.

Ayoub El Kaabi scored a hat-trick, with two of his goals coming in the opening half hour as the Greek side stunned the home fans at Villa Park to take a 2-0 lead.

Ollie Watkins reduced the deficit for Unai Emery's side on the stroke of half-time before Moussa Diaby equalised moments after the interval.

Olympiacos then roared back in front through El Kaabi's penalty, sealing his treble, and a deflected strike from Santiago Hezze.

Douglas Luiz missed a late penalty which means Villa must overturn a two-goal margin in the second leg in Piraeus on 9 May to reach their first European final since 1982.

El Kaabi began the goal flurry with a clinical finish. It was initially disallowed for an offside, but that was overturned by the video assistant referee (VAR).

The Morocco striker added a classy second when he latched on to Daniel Podence's clever pass over the top and slipped the ball under Robin Olsen.

Watkins pulled a goal back for Villa in added time in the first half with an angled finish from just outside the six-yard box.

Diaby then levelled as Konstantinos Tzolakis was beaten at his near post.

Villa seemed to have the momentum at that point but were sucker-punched by their visitors.

Douglas Luiz handled a Panagiotis Retsos header and El Kaabi coolly sent Olsen the wrong way from the resulting spot-kick to take his tally to eight goals in the competition.

There was more than an element of fortune to Olympiacos' fourth as Hezze's speculative effort flicked off the back of Ezri Konsa to wrong-foot Olsen.

Douglas Luiz had a late opportunity to atone for his error after David Carmo felled Jhon Duran but, to the incredulity of the home fans, he failed to hit the target.