The singer shunned a regular glass when she hit the Sugar Ultra Lounge club for a bash in her honour.
She kept up the boozing at a beach photoshoot yesterday, when she was snapped swigging beer in a tiny bikini.
RiRi showed off her famous figure in a string of smouldering shots before heading out to sea on a jet-ski ride with pals.
Rihanna tweeted: “Threw Bravo a birthday ba$h at mama Fenty crib!! #85 blessed yearz! Many more to you Grandfadda!”
The pensioner’s party featured a massive cake replica of a bottle of his favourite beer.
Rihanna rounds off her Diamonds world tour this month with a final performance in New Orleans on November 15.