CERTIFIED TWITTER STAR. Justin Bieber now has 33,371,792 Twitter followers. Photo from the Justin Bieber Facebook page

LOS ANGELES, USA - It took two days longer than expected, but Justin Bieber succeeded Tuesday in overtaking fellow pop idol Lady Gaga as the most followed person on Twitter.

"After putting up a great fight (which took longer than we expected), Justin Bieber took Lady Gaga's crown this early morning," Twitter Counter, which tracks and monitors Twitter usage, reported on its blog.

Screen shot from the Justin Bieber Twitter page

By mid-day, the Biebs had 33,342,299 followers, against 33,333,682 for the Mother Monster, followed by Katy Perry, Rihanna and, a day after his public second-term inauguration, President Barack Obama with 26,183,711 followers.

Last week Twitter Counter had forecasted that, according to its algorithms, Bieber would clinch first place last Sunday.

Screen shot from the Lady Gaga Twitter page

Bieber and Lady Gaga -- who had led the Twitter pack since 2010 when she outpaced Britney Spears for the top spot -- are currently on tour in the United States.

Lady Gaga posted this tweet in reaction to the news:

So proud of @justinbieber and all the Beliebers! I'm only happy to see your fans growing in size, you all deserve it! Monsters support you!

— Lady Gaga (@ladygaga) January 16, 2013

- Rappler.com