Gallery Dustin Poirier def. Justin Gaethje at UFC on FOX 29: Best photos view 13 images GLENDALE, Ariz. – In a bout that delivered on every bit of the expectations surrounding it, Dustin Poirier scored a fourth-round stoppage of Justin Gaethje . The lightweight bout was the main event of today’s UFC on FOX 29 show at Gila River Arena in Glendale, Ariz., near Phoenix. It aired on FOX following prelims on FOX and UFC Fight Pass. With the crowd chanting his name to start the fight, Gaethje pushed forward as you’d expect, throwing out low kicks and big right hands