BA 391 then BA 137 at Heathrow
Brussels → London → New Delhi
Timetable, London time
16:20BA 391 from Brussels at the gate
15:05BA 137 to New Delhi leaves the gate
22 h 45 apart on the timetable, overnight
BA 137 leaves 22 h 45 after BA 391 arrives on the timetable: more than half a day, so not a connection we count.