AC 4121 then BA 1782 at San Francisco
Ontario → San Francisco → Chicago O'Hare
Timetable, San Francisco time
17:50AC 4121 from Ontario at the gate
14:18BA 1782 to Chicago O'Hare leaves the gatealso AA 1948, AY 4140
20 h 28 apart on the timetable, overnight
BA 1782 leaves 20 h 28 after AC 4121 arrives on the timetable: more than half a day, so not a connection we count.