She got the lowest vote, and was about to go. At that time, it seems to be over for her. She wasn't surprised. Like a real sport, she started singing her 'farewell' song.
While singing – Jennifer Lopez went up the stage, "Give me that mic! This is crazy! We're using the "save." You ain't goin' home! Go sit down!"
(A "save" is a one-time privilege of the judges to keep a contestant from being eliminated – it needs to be unanimous) Randy, Steve and Jennifer agreed to use this privilege to keep her on the show.
When Seacrest asked her how she felt, Jessica responded...
"I don't expect anything. I just do what I do. Whatever happens happens, and I just want people to know that I've been working hard my entire life..."
She may have the lowest vote that night, but she got the vote of the people who mattered – the judges.
The Takeaway – Go out there. Take a risk and do your best. When it gets tough, the people who "count the most" will vouch for your work.