Justin Bieber has congratulated Lady Gaga on topping Forbes magazine's annual list of the the most powerful celebrities in the world.
The singer replaced Oprah, who fell to number two, following a year that has seen her earn $90 million from her Monster Ball World Tour.
Bieber, who was a new entry at number three, congratulated Gaga over Twitter: ''this is crazy...congrats to @LadyGaga for topping the list. well deserved. - http://onforb.es/mMvEyZ''
The 17-year-old has earned $53 million over the last twelve months from touring, music sales and his 3D movie.
Other celebrities on the list include Bono, Simon Cowell, Tiger Woods and Elton John.
Meanwhile, Fans of Lady Gaga have praised her new album 'Born This Way', which was made available to listen to online yesterday (May 18).