On his biggest tournament of his career, he was matched up against the towering South African fighter Jan "The Giant" Nortje.
Alexander Ustinov won the battle but unfortunately was unable to continue due to a deep laceration on his shin and was replaced by the American Scott Lighty.
Ustinov made two successful defences of that title against Italian Paolo Vidoz and Russian Denis Bakhtov.
In his 19th professional contest he defeated American future heavyweight title challenger Monte Barrett by unanimous decision.
On 25 November 2017, he unsuccessfully challenged for the WBA (Regular) heavyweight title, losing a unanimous decision to Syrian Manuel Charr.