The 36-year-old singer hosted the awards show at MGM Grand Garden Arena in Las Vegas, Nevada, and after she performed her song "Whole Lotta Woman," she had a brief run-in with former Idol judge Simon Cowell on stage.
"Hi everyone," Cowell, sporting his signature deep V neckline, spoke into the mic after giving Clarkson a hug. "That was bloody fantastic. What can I say? I'm very proud of you."
The reality competition judge and producer was actually at the awards show to introduce another one of his discoveries, Camila Cabello, who performed her new song with Pharrell, "Sangria Wine," as well as her hit "Havana."
Besides her Billboard Music Award hosting duties, Clarkson currently serves as a coach on The Voice. In a February interview with ET, the mother of two called out Idol, 16 years after she became the show's first winner, for failing to deliver part of her grand prize.