BA 893 then QF 2 at Heathrow
Sofia → London → Sydney
Timetable, London time
22:30BA 893 from Sofia at the gate
20:10QF 2 to Sydney leaves the gate
21 h 40 apart on the timetable, overnight
QF 2 leaves 21 h 40 after BA 893 arrives on the timetable: more than half a day, so not a connection we count.