Watch UFC Fight Night 142: dos Santos vs. Tuivasa (2018) : Full Movie Online Free UFC Fight Night 142: dos Santos vs. Tuivasa was a mixed martial arts event produced by the Ultimate Fighting Championship that was held on 2 December 2018 at Adelaide Entertainment Centre in Adelaide, South Australia. A heavyweight bout between former UFC Heavyweight Champion Junior dos Santos and Tai Tuivasa served as the event headliner.