When Julianna Pena submitted Amanda Nunes in December, it was considered arguably the biggest title upset in UFC history. Given Nunes’ (21-5 MMA, 14-2 UFC) status as who many considered the greatest women’s fighter in history, and the fact she held two belts when she lost the 135-pound title to Pena, a rematch is a strong likelihood with new champ Pena (11-4 MMA, 7-2 UFC). In fact, UFC president Dana White said he thinks a rematch “will probably be the biggest women’s fight of all time.” Felicia Spencer , who recently announced her MMA retirement , knows a few things about Nunes.