Judges unanimously scored the fight 30-26, 30-26 and 29-27 in favor of Jackson, who was relentless with her grappling offense against the formerly undefeated Russian fighter.
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Yankova, who could previously boast five wins and zero losses under the Bellator MMA banner, returned to action after a year-long break, as her last bout at Bellator 176 took place in April 2017.
Jackson seemed to have successfully rebounded from her defeat to former UFC title challenger Valerie Latoruneau at Bellator 191 last December, which became her only loss in the past eight bouts.