Tyson Fury was pictured watching over KSI as he prepared for his bout with Tommy Fury at the AO Arena in Manchester.
The 35-year-old entered in JJ's changing room as his gloves were being prepared, perhaps getting in the head of the YouTuber-turned-boxer.
Tommy will be looking to extend on his record of 9-0, with half-brother Tyson in attendance and even speaking about his upcoming fight with Francis Ngannou.
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There has been plenty of controversy in the build up to the fight, with Tommy's dad John Fury even involved in his own altercation with KSI at the open training session.
Tyson watched over keenly as KSI's team helped the 30-year-old prepare for his fight, giving an insight into further mind games deployed by the Fury family.
Having turned up in support of his brother, Tommy will be bidding to register his second boxing victory of the year, after beating Jake Paul in Saudi Arabia earlier this year.
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KSI has fought a total of five times, with four of those exhibition contests. His only professional victory came against Logan Paul back in 2019.
With millions expected to tune in across the evening, a sold-out arena in Manchester has housed many online superstars on the undercard including King Kenny, Salt Papi and Astrid Wett.
Fans online also reacted to Tyson's appearance, after he hopped into the changing rooms to show his face.
''Nice to see his brother showing support for Tommy's fight,'' tweeted one fan.
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Another jumped to the support of the heavyweight champion, adding: ''Not so mouthy now is he.''
''Funny that KSI isn’t talking s*** about Fury now? Thought he was ducking Usyk the other week??,'' said another.
''Fair play, that’s an excellent bit of mind games. Tyson knows JJ can win over Tommy,'' posted another online.
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Featured Image Credit: DAZNTopics: KSI, Tyson Fury, Tommy Fury, Boxing, YouTube