IT’S A RUDY AWAKENING

Not everyone booed Rudy Giuliani on his 74th birthday.

The now-single ex-mayor (above) threw himself a combination birthday and housewarming party in his brand new, unfurnished, bachelor pad near 86th St. and Park Ave. over Memorial Day weekend. Former Attorney General Michael Mukasey, Police Commissioner-turned-convict Bernard Kerik and Cooper Classic Cars owner Elliot Cuker were among the guests who helped Giuliani christen his new digs and blow out candles.

Despite already owning an apartment in Manhattan, a home in the Hamptons and a condo in Palm Springs, President Trump’s latest attack dog had been staying at the Sheraton hotel since his third wife, Judith, filed for divorce in April.

Giuliani also celebrated the big day Monday at Yankee Stadium, where he was treated to a Bronx cheer in front of 46,583 fans and a national TV audience. The Yankees lost the game to boot.