Dangerous Paradise by Barbara Nolan

Eddie Morgan, the Harley-riding owner of Manhattan mega-club Beyond Paradise, has a secret: Illegal, underground cage fighting in dingy basements. It keeps the dark days of addiction at bay and quiets the static in his brain.
Paige Drake, New York heiress to the Drake Hotel dynasty, has one last chance to prove her worth in the family business: Upgrade the outdated hotel bars.
When a dinner party from hell throws these total opposites together their tantalizing teasing and sparring words awaken deep feelings neither one knew existed.
Even though the Long Island socialite is way out of Eddie’s league, he can’t resist the challenge, and soon Paige finds herself zooming out of her buttoned-up life on the back of Eddie’s Harley. He agrees to help Paige with her business venture but soon realizes that her club promoter is a member of a vicious Russian drug cartel using Paige’s bars as a front for their drug operation.
Is Eddie willing to throw himself back into a life that nearly destroyed him to save Paige? And is Paige willing to face the seedier side of Eddie’s world and accept his gritty methods of dealing with the cartel?
Eddie and Paige’s story twists and turns as two divergent people struggle to find common ground in a world where rules do not apply.