In his first world title fight on 13 December 2014, Korobov faced
Andy Lee for the vacant
WBO middleweight title. Even though he was doing well for the first five rounds, the Russian would end up hurt and then knocked out in the sixth round, losing his opportunity to become a world champion for the first time in his career. On 22 December 2018,
WBC middleweight champion Jermall Charlo was slated to defend his belt against
Willie Monroe Jr. However, Monroe Jr's VADA tests came out positive for a banned substance, which meant a new opponent for Charlo was in the works. Korobov ended up being the substitution and gave Charlo a very tough fight, however, was still unable to come out with the win. Korobov started the fight really strong, but gave up the latter part to the WBC champion. After a controversial
majority draw against Immanuwel Aleem, Korobov,
WBA's number #3 at middleweight at the time would go on to fight WBA's #1,
Chris Eubank Jr. for the vacant WBA
interim middleweight title, which was also the final eliminator for the full
WBA middleweight title. Korobov lost the fight by a second-round TKO after suffering an injury to his left shoulder. Korobov retired from sports in 2023. ==Professional boxing record==