LAS VEGAS — Israel Adesanya learned that holding two UFC title belts simultaneously is not nearly as easy as Amanda Nunes makes it look. And Petr Yan learned that even a momentary lapse in discipline can dearly cost a champion. Jan Blachowicz defended his UFC light heavyweight title with a unanimous decision over the previously unbeaten Adesanya at UFC 259 on Saturday night, thwarting the reigning middleweight champ’s bid to claim a second belt. Two-division champion Nunes defended her featherweight belt with ease, beating Megan Anderson by submission 2:03 into the first round at the Apex gym on the UFC’s corporate campus.