*Before Floyd Mayweather Jr. manhandled Sugar Shane Mosley to retain his welterweight title Saturday night in Las Vegas, Chris Brown left a mark of his own on the pre-fight National Anthem – a performance that is receiving mixed (mostly bad) reviews.

While some fans thought his run-filled version of the “Star Spangled Banner” was just fine, others took to the Internet and Twitter calling it a hot mess. Brown defended his performance with the tweet: “Im human. how many of u r perfect????????”

Many in the blogosphere thought it was inappropriate for Brown to perform at Saturday’s match given that he used his fists on former girlfriend Rihanna.

In other Chris Brown news…

While the singer is still looking for a club to celebrate his 21st birthday, it was his age this time – not his assault conviction – that left him standing outside Saturday night at Vegas club Tao Beach, according to the New York Post.

Brown likely thought the bouncers would let him slide since his 21st birthday was just four days away on May 5, but the venue turned him away for being underage. Meanwhile, Jamie Foxx, Anna Paquin, Stephen Moyer, Busta Rhymes and Nelly were among the celebs who made it inside.