UA 3851 then AY 4100 at San Francisco
Rio De Janeiro → San Francisco → Los Angeles
Timetable, San Francisco time
17:41UA 3851 from Rio De Janeiro at the gate
15:07AY 4100 to Los Angeles leaves the gatealso EI 7152
21 h 26 apart on the timetable, overnight
AY 4100 leaves 21 h 26 after UA 3851 arrives on the timetable: more than half a day, so not a connection we count.