FR 6927 then GQ 821 at Fiumicino
Barcelona → Rome → Athens
Timetable, Rome time
18:40FR 6927 from Barcelona at the gate
13:00GQ 821 to Athens leaves the gate
18 h 20 apart on the timetable, overnight
GQ 821 leaves 18 h 20 after FR 6927 arrives on the timetable: more than half a day, so not a connection we count.