US pop superstar Katy Perry has shared heartwarming videos of her meeting with young Adelaide fan Grace Moores, lauding the "power of the internet" for bringing the eight-year-old's plight to her attention.
The Teenage Dream singer posted the footage on her Instagram account today, showing her singing her chart-topping hit Firework with Grace — who's battling brain cancer — in the family's Banksia Park home.
"Grace, you know you're probably the first person I've ever come to their house and done a concert for," Katy tells her.
Grace underwent emergency surgery last Wednesday, preventing her from attending Katy's concert on Monday night.
