That fan, who boldly asked the British singer if she could sing with her, was Grammy-nominated Christian artist Jamie Grace.
The Atlanta-based singer told ABC News she, along with her sister Morgan and brother-in-law, scored front row seats to the concert. Grace said she was giving herself an early birthday present, though her big day isn't until November.
"She was being super interactive with her fans," Jamie Grace recalled, "and then she looked at me and I said, 'Do you want to sing together?' And she said, 'Okay, come up here!' So I went up there."
It was just like Jamie Grace, 24, imagined it. Apparently, she had been joking earlier with people sitting around her at the concert, saying she and Adele would sing together later.
"I was excited and blown away and honored in general," she said. "I was nervous. I was excited. I was literally shaking."
It wasn't the first time that Jamie Grace played at the Staples Center, but this time was special.
"To be up there with Adele it's a totally different thing," she clarified. "It wasn’t an audience ... where they came to see me."
The singer added, "The last time I was at Staples it was when I was nominated for a Grammy when I was 19 and so it's funny because [Adele] had no idea of any of that and she still gave me that chance."
While Jamie Grace was onstage, Adele said hopefully the moment would help the young singer score an album, not knowing that Jamie Grace already had two under her belt.
Still, the words didn't fall flat, Jamie Grace said, because she had been contemplating whether to stop pursuing music as a career.
"Just because you're an artist and you're on the radio or you have a Grammy nomination, people might think that everything is good," she said. "I've actually been going through a really emotional time with music and have just been really overwhelmed with what’s next in my career."
Jamie Grace said she had been in counseling to help her with the decision, but the moment Adele gave her on the stage was what has swayed her towards continuing to create music.
"Even though I have this recognition and this career, to be given the opportunity to sing for Adele’s crowd -- it was a reminder and an assurance that I do have a voice and the voice does matter. It was everything I needed."
Jamie Grace said although she's tweeted Adele a few times, the singer hasn't responded just yet. "That would be just icing on the cake," she gushed.
Still, the singer hopes to work with Adele, who is currently touring to support her album "25," soon.
"I'm a dreamer so I have no shame. I would love to write with her one day," she said. "Me, her and my sister could do a three-part harmony. She can take the lead."