Amanda Serrano is on top of the world – that’s how it feels, anyway, standing on the 86th-floor observation deck of the Empire State Building on a misty Tuesday afternoon. As the seven-division champion from Brooklyn’s Bushwick neighbourhood poses for photographs, the city unspools behind her, offering an evocative glimpse of Madison Square Garden. In the storied venue’s 140 years of hosting boxing, a women’s fight has never headlined a card – until Saturday night, when Serrano will climb through the ropes to challenge Ireland’s Katie Taylor for the undisputed lightweight championship.