Cynthia Calvillo dominated Jessica Eye to secure a unanimous-decision victory in Las Vegas on Saturday.
Calvillo controlled Eye for most of their flyweight fight and it was eventually scored 49-46, 49-46 and 48-47 in her favour.
Eye, the top-ranked flyweight contender, made a decent start before Calvillo (9-1-1) dominated from the second round.
"I feel great, especially for putting on a performance like that with a short amount of training," Calvillo told ESPN after her win.
"We're going through crazy times so it just feels amazing to be able to do this during this time."
Calvillo took Eye down numerous times, including inside a minute in the fourth round.
Urged to land a decisive blow, Eye (15-8) was unable to in the final round as Calvillo was awarded a deserved victory.