HH 575 then SQ 391 at Istanbul
Tashkent → Istanbul → Singapore
Timetable, Istanbul time
17:50HH 575 from Tashkent at the gate
13:15SQ 391 to Singapore leaves the gate
19 h 25 apart on the timetable, overnight
SQ 391 leaves 19 h 25 after HH 575 arrives on the timetable: more than half a day, so not a connection we count.