Yaroslav Amosov assumed his combat sports career was over.
Amid the Russian invasion of Ukraine in late February 2022, the Ukrainian mixed martial arts champion (MMA) abandoned plans to headline a world title bout in London and was instead on the streets of Irpin, just outside Kyiv, with an assault rifle in his hands.
“I think, OK, now I go to defend my city and I don't think about my career,” Amosov recalled to RFE/RL in a call from his base in Florida.
After evacuating his wife and infant son out of Irpin in the hours following the Russian onslaught he says, "I called my friends and we met and talked about what we do and in the evening went back to my city and went to the war."
Despite Russian forces being widely expected to capture all of the Kyiv region, Amosov decided, “I’ll stay in my city” he said.
By late March, the invading army was struggling to hold Irpin amid counterattacks from Ukrainian forces that included locals such as Amosov and his friends, who knew the city and its surrounding forests inside out. It was then that the former MMA star, who held a flawless professional record of 26 victories with no losses, was reminded of his former life.
In a suburb of Irpin, Amosov’s welterweight world championship belt from Bellator -- America’s then second-largest MMA promotion, lay hidden in the basement of his mother’s home where some of the fiercest fighting had taken place.
"A couple of guys said to me: ‘Maybe you will get your belt,'" Amosov recalled, “I said: 'OK, let’s go, because now this is more safe.'"
The fighter took directions from his mother by telephone as he searched the basement of the home where he had lived as a child. As he emerged triumphant with the trophy, his comrades laughed that he was claiming the belt “for the second time.”
By the spring of 2022, central and northern Ukraine was largely cleared of Russian forces and Amosov’s friends and family began pushing for him to consider returning to the octagon to revive his long-held goal of joining the Ultimate Fighting Championship (UFC), the world’s premiere MMA promotion.
“I don’t know [whether I should] do this or no, but my manager, Andrew, said ‘you must go to the training, maybe you can [make a statement] after the fight and help your city and your country more,’” Amosov recalls. On his return to MMA in November 2023, the Ukrainian suffered his first professional defeat, before winning his 28th victory in March 2025. He was signed to the UFC in November of that year.
He is now seen as a top prospect for the UFC’s ferociously competitive welterweight division after winning a first-round submission victory in his UFC debut over veteran American fighter Neil Magny on December 13 in Las Vegas.
Amosov has a background in combat sambo, a fighting technique developed in the 1920s for the Soviet Red Army. The discipline often produces MMA fighters who favor strangling submission expertise over punches and kicks.
The Ukrainian holds a career record that reads like a glossary of submission techniques, from “north-south choke” to the elbow wrenching “armbar.”
Amosov says being at war has made tough training regimes and weight cuts seem relatively easy, and helped him channel nerves that can gather like a storm before a big fight. “You need to control this chaos,” he said of pre-fight stresses. “If you have experience, for you this is controlled much better.”
Conversely, he says, the physical fitness he maintained as a sportsman was crucial on Ukraine's battlefields. “I'm not tired, I can walk, I can run,” he says, adding that many other volunteers in Irpin would finish their days with bruising and back pain from wearing heavy body armor. "That's why your physical [conditioning] is very important in the war,” he said.
But he stresses that combat in the octagon and fighting in the military differ profoundly.
In a post-fight press conference following his UFC debut, Yaroslav hinted at some of the horrors he says he witnessed in Irpin, including seeing a toddler being carried to safety covered with his father’s blood.
Referencing the common MMA parlance to describe violent and drawn-out bouts as “wars” he told reporters: “Guys, if you don’t know what is war, shut up.”
