The 32-year-old pop diva joined Pitbull on stage for a live performance during Tuesday night's "Voice" finale, which crowned 16-year-old Danielle Bradbery the winner of the fourth season.
"Voice" fans hadn't seen Christina Aguilera on stage since she left after season three to work on her music career, but the blonde bombshell returned Tuesday looking much slimmer than years past. US Weekly estimated that the diminutive performer had shed 20 pounds off of her 5-foot, 2-inch frame.
She showed off her new look in a bandeau skirt and see-through mesh top.
"How cool was that seeing Christina tonight?" coach Blake Shelton told reporters. "She looks amazing, by the way."