The US hitmaker (23) was knocked back by the popular haunt in favour of a regular student night.
Twentyone Club and Lounge on D'Oiler Street said that they were "too busy" to entertain the star following his gig at the O2 last night (left).
Instead, the club hosted its normal 'Monday Night Madness' event.
The R'n'B singer, who stayed at the Conrad hotel, took to the stage shortly before 9pm and performed a medley of some of his best-known hits.
A spokesperson for the Twentyone Club told the Herald: "We are very busy so we just couldn't do it."
Brown and his crew reportedly partied at the nearby Grafton Lounge.
Just weeks after Brown's 2009 Dublin appearance, he beat up his girlfriend Rihanna. His current tour has been shrouded in controversy, with women's groups calling on people to boycott the concerts.