She killed it! Melanie Amaro is the "unofficial" winner of The X Factor USA.

Melanie Amaro is Simon Cowell‘s last girl standing and the potential winner of “The X Factor USA” come December 22, 2011. However, Nicole Scherzinger‘s Josh Krajcik and LA Reid‘s Chris Rene can still make a possible upset next week.

Watch Amaro’s sterling performance during the Top 4 show here: