OS 772 then FR 751 at Vienna
Sofia → Vienna → Porto
Timetable, Vienna time
13:10OS 772 from Sofia at the gate
11:35FR 751 to Porto leaves the gate
22 h 25 apart on the timetable, overnight
FR 751 leaves 22 h 25 after OS 772 arrives on the timetable: more than half a day, so not a connection we count.