The 250 guests were served Diddy's Ciroc vodka and Veuve Cliquot champagne and the 'I'll Be Missing You' hitmaker toasted Naomi and the Russian billionaire midway through the evening.
Diddy was also heard urging his pal Kanye to smile for photographers.
According to the New York Post newspaper, he said: "You always look moody".
Naomi - who has been in a relationship with Vladislav since 2008 - recently threw a lavish party to mark her boyfriend's birthday in Jaipur, India.
Naomi, 42, and Vladislav were joined by many famous guests including Kate Moss, Vivienne Westwood, Bob Geldof, Demi Moore and Sarah Ferguson, the Duchess of York, to enjoy a 1930s-themed dinner, with entertainment from Diana Ross, Chaka Khan and Bluesman Buddy Guy.