AC 4121 then CX 7912 at San Francisco
Ontario → San Francisco → San Diego
Timetable, San Francisco time
17:50AC 4121 from Ontario at the gate
11:53CX 7912 to San Diego leaves the gate
18 h 03 apart on the timetable, overnight
CX 7912 leaves 18 h 03 after AC 4121 arrives on the timetable: more than half a day, so not a connection we count.