Justin Bieber has overtaken fellow pop star Lady Gaga to become the most popular celebrity on Twitter.com.

The Poker Face hit-maker broke a number of records as she clocked up millions of followers on the social networking website, but the teenage singer has always been hot on her heels and he has now officially overtaken Gaga to rack up the most online followers.

Both stars have been hovering around the 33 million mark, but Bieber overtook his rival by several thousand on Monday night.

Gaga acknowledged Bieber's growing Twitter.com fan base earlier this month, writing in a message to the teenager, "So proud of Justin Bieber and all the Beliebers! I'm only happy to see your fans growing in size, you all deserve it!"

Gaga has held the title of 'most followed' user on the website since she overtook previous Twitter queen Britney Spears in 2010.

The singer and her teenage rival are followed by Katy Perry in third place, while another singer, Rihanna, is in fourth ahead of President Barack Obama.

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