He received coaching from Gagik Sargissian and Melikset Khachiyan before entering a chess academy in 2002, where he was occasionally instructed by GM Arsen Yegiazarian and IM Ashot Nadanian.

[4] In the same year he won a team gold medal (together with Levon Aronian, Vladimir Akopian, Gabriel Sargissian and Artashes Minasian) at the 38th Chess Olympiad in Dresden.

[5] In 2011, Petrosian tied for 1st–3rd with Marat Dzhumaev and Anton Filippov in the Georgy Agzamov Memorial in Tashkent and won the event on tie-break.

On 1 October 2020, Wesley So, the eighth highest-rated grandmaster in the world at the time, accused Petrosian of cheating in his semi-final and final games during the online Chess.com 2020 PRO Chess League.

Stop playing with my name, i deserve to have a good name during whole my chess carrier, I am Officially inviting you to OTB blitz match with the Prize fund!

I suggest all other people who's intrested in this situation, just take a look at my results in 2016 and 2017 Blitz World championships, and that should be enough... No need to listen for every crying babe, Tigran Petrosyan is always play Fair !

Liers will kicked off... [sic][17][18] Chess.com subsequently determined that Petrosian had violated fair play regulations; consequently, his team the Armenia Eagles, was disqualified and So's Saint Louis Arch Bishops were crowned champions.