Organisers screened England’s Euro 2024 football quarter-final win against Switzerland inside the arena, with undercard bouts taking place during the intervals.
Hearn, former world champion Tony Bellew and ex-England footballer Jamie Redknapp jumped out of their seats after England’s penalty shootout victory.
Fisher – who reportedly sold 4,000 tickets alone – later captured the feel-good energy with a career-best win.
With a 24lb weight advantage, he appeared levels above from the opening bell and it did not take long for his power to show.
Fisher boasts a loyal fanbase, thanks in thanks in large to his social-media star father, ‘Big’ John Fisher.
Armed with their “bosh” catchphrase, the pair regularly document their lives and love for Chinese takeaways online.
But the Essex fighter demonstrated he is more than just a social media gimmick against – on paper – his toughest opponent to date.
“I was expecting a 10-round war, Fisher said.
“I’ve really matured over the last six months and I really think we can go as far as we want in this game.”
