Postol made his professional debut on 1 October 2007 at the age of 23 against Zsolt Vicze, stopping him in round 2.
He won his next fourteen bouts fighting in countries Bosnia and Herzegovina, Ukraine, Spain, Russia and Georgia.
[2][3][4] After vacating the belt, it was announced in February 2013 that Postol would next fight American boxer Hank Lundy for the vacant WBC International light welterweight title.
On 7 November 2013, the World Boxing Council ordered a final eliminator for their super lightweight title, held at the time by unified champion Danny García, which would see Postol fight Turkish boxer Selçuk Aydin (26-2, 19 KOs).
[7] Before engaging in the eliminator, Postol finished the year with a dominant decision win over tough journeyman Behzod Nabiyev (22-6-1, 16 KOs) at the SportLife club in Kyiv, Ukraine.
On his American debut, Postol stopped Aydin in round 11 to become the mandatory challenger for the WBC title.
[14][15] Having not fought in December 2014, in January 2015, Postol announced that he would fight on the undercard of Danny García vs. Lamont Peterson on 11 April at the Barclays Center in New York.
[18] It was announced that Postol would fight Lucas Matthysse (37-3, 34 KOs) in a scheduled 12 round bout for the WBC light welterweight title vacated by Danny García in order to move up to the welterweight division in August, at the StubHub Center in Carson, California on 3 October 2015.
[19] The camps made a deal just in time to avoid a WBC purse bid scheduled for Monday.
Matthysse got to one knee, but with his head down and dabbing at his eye, referee Reiss counted him out at 2 minutes, 58 seconds.
[21] On 3 May 2016 it was finally confirmed that Postol and Terence Crawford had officially signed a contract for a highly anticipated junior welterweight unification fight on 23 July at the MGM Grand in Las Vegas.
[22] Crawford won by unanimous decision and unified two light welterweight world titles before a crowd of 7,027.
Ringtv announced that Postol, who was still ranked by the WBC at #3, would fight inexperienced Uzbekistani boxer Jamshidbek Najmiddinov (14-0, 9 KOs) on 16 September 2017.
I have been ready to fight within all that time, with any opponent, but the question why I was absent should be directed to my manager.” His manager Vadim Kornilov answered, “We have been looking for the right opportunities for Postol in the United States and it’s been hard to get a TV spot for a non-U.S. fighter lately.
[28] The WBC super lightweight title became vacant after Terence Crawford decided to move up to welterweight.
[29] In January 2018, a deal was finally reached for the fight between Postol and Prograis to take place on 9 March at the Buffalo Run Casino in Miami, Florida.
[30] On 12 February, ESPN reported that Postol suffered a fractured thumb and then forced to drop out of the bout.
[31] On 26 April 2018, Cyclone Promotions announced Postol would be fighting their 27 year old rising prospect Josh Taylor at the SSE Hydro in Glasgow on 23 June, with Taylor defending his WBC Silver title and a chance for the winner to become a step closer to challenging for a world title.
[35] On 24 October, Postol was announced by the World Boxing Super Series as a reserve fighter for Josh Taylor vs. Ryan Martin on 3 November 2018 at the SSE Hydro in Glasgow.
[37] On 19 March 2019, it was announced that Postol would fight French boxer Mohamed Mimoune (21-2, 2 KO) in a WBC final eliminator on 27 April.
[38] The fight was confirmed a week later to be part of a Showtime tripleheader featuring Robert Easter Jr. vs. Rances Barthelemy at The Joint at Hard Rock Hotel & Casino in Las Vegas.
[39] Postol defeated Mimoune by a 10 round unanimous decision to become a step closer to challenging WBC champion José Ramírez.