The teenage star, who performed a cover of Prince's 'Purple Rain' on this week's show, confessed to being a fan of Zipparah Tafari's 'Lost My Keys' rap.
"What he did was funny and it's a really catchy song," she told Digital Spy. "Everyone loves him, I think he's great. So yeah, he's definitely competition."
Redfern also laughed at suggestions that her grandmother, a former stage star, should audition for Britain's Got Talent as well.
"I think she really enjoyed what she did when she was younger and now she just wants me to do really well," the former X Factor hopeful said. "She's really supportive.
"[My nan] just sang around the club scene, she never took it really seriously. But she always wanted to."
However, Redfern did say that her nan has become more famous than herself since the show aired.
"We went out for dinner the other day and people were like, 'It's the nan and the singer'," she revealed. "They remember her more."
Britain's Got Talent continues Saturday (April 14) at 8pm on ITV1.
> 'Got Talent' Chelsea Redfern: 'X Factor snub made me more determined'
Watch Chelsea Redfern's Britain's Got Talent audition below: