He competed in the 1960 Summer Olympics, but lost in the third bout to the eventual winner Francesco Musso in a close decision (2:3).

Soviet authorities and the KGB intercepted and suppressed their mail, threatening Nikinorov with repercussions if he didn't stop communicating with Fuchs.

[1] Later in 1989, when the Soviet union was crumbling and its citizens were finally allowed to leave the country, he traveled to the United States, but didn't meet Fuchs, as both were married by the time.

[1][3] As a teenager Nikonorov wanted to become an association football player, but was rejected at various clubs because of his small size.

In retirement he coached boxers in his club Trudovye Rezervy, and was also involved with the Bulgarian (1970–74) and Soviet (1989) national teams.