The Oscar and Grammy-winning performer, who looked slim in a black top and black jeans, took the stage on Thursday to sing 'Inseparable' with finalist Candice Glover, reported People magazine.
Hudson, 31, who was one of the contestants of the third season of the show, also let Glover, 23, have her a moment in the spotlight at the end of the song when she stood back and said, "Sing it, Candice."
The performance got a standing ovation from the judges.