4Z 754 then SA 539 at Johannesburg
Mthatha → Johannesburg → Durban
Timetable, Johannesburg time
09:504Z 754 from Mthatha at the gate
09:20SA 539 to Durban leaves the gate
23 h 30 apart on the timetable, overnight
SA 539 leaves 23 h 30 after 4Z 754 arrives on the timetable: more than half a day, so not a connection we count.