PN 6381 then ZH 121 at Guangzhou
Zhengzhou → Guangzhou → Hanoi
Timetable, Guangzhou time
11:30PN 6381 from Zhengzhou at the gate
11:25ZH 121 to Hanoi leaves the gate
23 h 55 apart on the timetable, overnight
ZH 121 leaves 23 h 55 after PN 6381 arrives on the timetable: more than half a day, so not a connection we count.