Celtic's Scottish midfielder Callum McGregor, pictured February 2018, got his team off to a flyer when he opened the scoring on 17 minutes

Glasgow (AFP) - Scottish champions Celtic failed to make the most of a man advantage as AEK Athens held out for a 1-1 draw in Glasgow on Wednesday to take the upper hand in their Champions League third qualifying round tie.

The hosts got off to a flyer when Callum McGregor rewarded a positive start from Brendan Rodgers’s men to open the scoring on 17 minutes.

But Celtic failed to build on their lead and were punished for one moment of slack marking when Belgian Viktor Klonaridis fired home a vital away goal just before half-time.

AEK, who ended Olympiakos’ seven-year reign as Greek champions last season, were made to defend deep in the second-half when Kostas Galanopoulos picked up two quickfire yellow cards to leave the visitors a man down.

But despite dominating possession, Celtic struggled to create chances and Olivier Ntcham’s stoppage time shot that curled inches over was as close as they came to a winner.

The sides meet again next Tuesday (August 14) with the winners progressing to face Swedish champions Malmo or Hungarians Vidi in the playoff round to reach the group stages.

“We knew they were a good side but we proved that we are also a good side and can go over there and get a result,” said Celtic boss Rodgers.

“We can score over there, I don’t think there is any question of that. We also have to defend well, as well.

“It was always going to be a difficult game for us, at 1-0 up or 1-1, we always thought we would have to go there and score.

“It is still very much in the balance. Of course it swings to them as they are at home but we certainly know we have the quality to go and perform, after seeing that this evening.”

On a good night for Greek sides, PAOK came from 2-0 down to take a 3-2 first leg lead over Russian giants Spartak Moscow.

Last season’s Europa League semi-finalists Red Bull Salzburg also edged towards the group stages for the first time with a 3-0 win over Macedonian champions Shkendija.