Standing side-by-side on stage, real-life couple Alex Kinsey and Sierra Deaton exuded an endearing, nervous charm. Simon Cowell even admitted he expected their act to be “quite corny”.However, as soon as they began reinterpreting “Toxic,” everything changed. Turning the high-energy pop hit into a slow, sultry, and harmonic folk-pop ballad, their undeniable chemistry and gorgeous vocal blend completely captivated the judges and the audience.

Earning four enthusiastic yeses, the duo skyrocketed through the competition under Cowell’s mentorship and ultimately won the third and final season of the show. Their “Toxic” audition proved that a great song can be entirely reinvented through raw emotion and genuine artistry.Watch Alex and Sierra transform a pop classic into a mesmerizing acoustic masterpiece during their audition: