Olympiakos and PAOK suffered one-goal losses on the road on Thursday that allow for some hope of recovery in the return legs next week in Greece.
Greek champion Olympiakos saw its early lead get reversed in the second half to go down 2-1 at Atalanta for the Europa League.
Fielding a team with three central defenders, Olympiakos manager Pedro Martins clearly had a defensive orientation.
With 15 minutes on the clock Olympiakos broke into an attack with Giorgos Masouras passing to Tiquinho and he sent a low yet powerful drive into the Atalanta net to stun the hosts against the run of play.
After an hour of pounding Atalanta got to score, and did so twice in three minutes, both with Albanian defender Berat Djimsiti and both from right-side corner kicks that the Reds’ defense was unable to deal with.
The Reds ought to be very cautious in the return leg, as the Bergamo team tends to be more prolific when playing away from home.
In the UEFA Conference League PAOK suffered a rather unexpected reverse in Denmark, going down 1-0 to Midtjylland.
A single lapse of concentration in defense sufficed for the Danish to take the lead, which they preserved for the rest of the game.
Joel Andersson was on target for the hosts on the 20th minute, with the Thessaloniki team being unable to respond. It will have to do so a week later in Toumba.