The 19-year-old singer from Rochester, Mass., began by telling Disney star and judge Demi Lovato that she had been heavily bullied throughout middle school and high school, as Lovato was when she was younger.
Lovato also publicly struggled with an eating disorder, depression and wound up in rehab during the holidays, Perez Hilton reported.
Jensen sang Jessie J's "Who You Are" during the audition and moved everyone to tears, even Cowell, who tried to keep a tough exterior.
Jensen continued to sing, though she began to cry after singing the lyrics, "it's okay to not be okay." But the crying didn't stop there; even after getting a standing ovation from the crowd, Jensen stood on the stage, tears flowing.
To top it off, Lovato got up from her seat behind the judges' table to comfort Jensen on the stage.
She privately told her, "It's okay. I know exactly what you've gone through and I've made it through and I know you can too. You are so strong. That was absolutely amazing. Oh my god, give me another hug."
Record executive and judge L.A. Reid told the contestant that she "had" it, that he had never heard anyone pour so much emotion into a song before.
Pop princess Britney Spears told Jensen that she had a beautiful, raspy, sexy voice.
It seemed Cowell had to continue eating mints to hold back his own manly tears, as he told her she was "incredible."
Lovato added, "You broke my heart when you sang."
Jensen got a "yes, yes, yes" from Spears and the "easiest yes all day" from Cowell.
Later a clip of Cowell was shown where he admitted to Lovato that he might have teared up a little during the show.
"I really felt for her, I did." He said, "I literally cried. I lost it. I've never ever done that he said to the make-up people."
"You seemed speechless," Reid told Cowell and he tenderly shook his head yes.
Twitter was also in shock after seeing Cowell's reaction:
"Still in shock that Simon Cowell cried lol. #XFactor" one fan of the show said.
"IF SIMON COWELL IS CRYING YOU KNOW ITS SOMETHING BIG OK," someone else tweeted.
"Jillian you made Simon Cowell cry. You've officially conquered the world," another praised Jensen.
Check out the YouTube clip to see Cowell's reaction at around the 8:05 mark.