EU 6677 then 9C 8559 at Pudong
Chengdu → Shanghai → Seoul
Timetable, Shanghai time
20:00EU 6677 from Chengdu at the gate
13:509C 8559 to Seoul leaves the gate
17 h 50 apart on the timetable, overnight
9C 8559 leaves 17 h 50 after EU 6677 arrives on the timetable: more than half a day, so not a connection we count.