Mamalis by TKO.
Round 1 - Rios with some hard leg kicks early. Mamalis drilling him with big shots now and Rios was close to finished but survives. Mamalis with a nice trip takedown and then lands a few punches before they're back to standing. Rios tries to jump up and grab a guillotine but Mamalis survives. Rios locks up a deep guillotine but Mamalis manages to pop his head out. Mamalis landing some nice long punches now. Rios is mostly working the leg kicks standing. Mamalis counters a leg kick with a punch and now he's landing big shots that drop Rios. Big shots from Mamalis and the fight is stopped. Nick Mamalis wins by TKO (strikes), round 1.