IB 986 then CX 1751 at Madrid
London Gatwick → Madrid → Buenos Aires
Timetable, Madrid time
23:00IB 986 from London Gatwick at the gatealso BA 4240, VY 5527
12:10CX 1751 to Buenos Aires leaves the gatealso BA 4255, AY 5375
13 h 10 apart on the timetable, overnight
CX 1751 leaves 13 h 10 after IB 986 arrives on the timetable: more than half a day, so not a connection we count.