We couldn't believe it when we saw the YouTube video of Greyson Chance playing the piano and singing Lady Gaga's Paparazz at a school concert.

The  talented 13-year-old performed on the Ellen DeGeneres show and was subsequently signed to a record label that the presenter set up especially for him.

And now Greyson has met the lady whose song got him several million hits on YouTube.

Greyson posted a photo of himself with Lady Gaga backstage at her concert and he couldn't look any happier!

Are you a fan of Greyson? Tell us on Twitter @areyouentwise

Greyson saw Gaga on her Monster Ball...