On 30 January 2020, Paul made his professional debut against fellow YouTuber AnEsonGib as the co-feature to the WBO world middleweight title bout between professional boxers Demetrius Andrade and Luke Keeler, in which he won via technical knockout in the 1st round.[8] After the fight, KSI and Paul exchanged words on stage.[9] KSI and Paul were then expected to face each other. However on 23 March, Prime MinisterBoris Johnson announced the first national lockdown in the United Kingdom in responds to the COVID-19 pandemic which prevented KSI from being able to train for the bout.[10] In the United States however, the restrictions were not as severe, thus allowing Paul to continue his boxing career.
On27 August 2022, KSI returned to boxing after a three year hiatus in an MF–professional bout.[15] Originally, KSI was scheduled to face fellow YouTuber Alex Wassabi, but was cancelled after Wassabi sustained a concussion.[16] Paul immediately took it to Twitter to call out KSI and offer him as his Wassabi's replacement. KSI declined his offer. On 8 August however, KSI tweeted an offer to Paul stating that they will fight in 2023 at Wembley Stadium with the winner taking 100% of the purse made from the event.[‡ 1][3] Paul accepted the deal.[‡ 2] On the night, KSI fought and defeated rapperSwarmz via knockout in the 2nd round and professional boxer Luis Alcaraz Pineda via knockout in the 3rd round.[17]
On14 January 2023, KSI fought and defeated Brazilian YouTuber FaZe Temperrr via knockout in the 1st round and immediately called out Paul.[18]On26 February, Paul fought professional boxer Tommy FuryinSaudi Arabia and lost via split decision.[19] After the bout, KSI's manager and Misfits Boxing co-president Mams Taylor, revealed that Paul's team had decided that they no longer wish to have a bout with KSI in August, instead choosing a bout with Nate Diaz, in which he won via unanimous decision.[20]On13 May, KSI fought professional boxer Joe Fournier and originally won via a controversial knockout in the 2nd round, but was later overruled to a no contest due to an unintentional elbow strike.[21] After the bout, KSI shared a stare down with Paul's former opponent Fury.[21]On14 October, KSI fought Paul's former opponent Fury, and lost via unanimous decision.[22] On 16 December, both KSI and Paul were active. Paul fought and defeated professional boxer Andre August via knockout in the 1st round while KSI and fellow YouTuber IShowSpeed held a charity spar for the Anthony Walker Foundation at the exact same time.[23][24]
In 2024, Paul was scheduled to face former undisputedheavyweight champion Mike Tysonon20 July but was postponed due Tyson suffering from a ulcer flare up.[25] On 1 June, Paul called out KSI on Twitter to step in for Tyson.[26] KSI responded by stating he has a bout scheduled in August and offers to fight in December.[27] Paul then leaked KSI was in negotiations to fight former unifiedlight welterweight champion Amir Khan, and offered to fight Khan in February 2025 if he immerged victorious.[28] Paul then offered KSI a fight in February at 200 Ibs at Madison Square Garden. KSI responded demanding the fight takes place in December at 185 Ibs.[29] The following day on 2 June, Mams Taylor confirmed that Paul will be receiving a contract for either December or February at 185 Ibs.[‡ 3] On 8 June, KSI uploaded a YouTube video proposing one final offer to Paul for May 2025 at 185 Ibs with the option to have the bout take place in the US rather than England.[30] However, Paul's manager and Most Valuable Promotions co-president Nakisa Bidarian stated that Paul is booked for May, and suggested February again.[‡ 4] Taylor responded to Bidarian and accepted the offer.[‡ 5] On 17 June however, Taylor confirmed that team Paul have been "radio silence" in negations.[31]