A professional mixed martial arts competitor since 2018, he has previously fought in AMC Fight Nights, where he held the Light Heavyweight Championship.
He made his debut at the WCSA Combat Ring - Steel Heart 9 tournament where he faced Makhmadsharif Mirzokhodzhaev.
[2] Petrosyan performed at the Fight Nights Global and WCSA Combat Ring - Steel Heart tournaments.
[2] Petrosyan faced Artur Aliskerov for the Fight Nights Light Heavyweight Championship on 28 August 2020 at MMA Festival: 75th Anniversary of the Great Victory.
[11][12] Petrosyan next faced Caio Borralho on July 9, 2022, at UFC Fight Night: dos Anjos vs. Fiziev.
[16] Petrosyan faced Christian Leroy Duncan on June 17, 2023, at UFC on ESPN: Vettori vs. Cannonier.
[17] Petrosyan was scheduled to face Rodolfo Vieira on November 4, 2023, at UFC Fight Night: Almeida vs. Lewis.