Deji, a YOUTUBE star, was defeated by Alex Wassabi, but it was only after a fan invaded the ring.
Oladeji Daniel Olatunji, the Londoner, had lost two fights before.
In 2018, he was beaten by Jake Paul, who is now a professional and last June by TikToker Vinnie Hacker.
He lost in a split decision at London's O2 Arena after just five rounds.
Deji is to be credited for his improvement in both his boxing and fitness for the venture into the ring.
Round two saw the bout descend into chaos when a celebrity supporter ran into it.
It is not clear why he did this other than to make virality - although he was all over the internet for the wrong reasons.
He was humiliatingly thrown out of the ring first, and his actions caused the fight delay to be temporarily.
Free Bets: Get more than PS2,000 in NEW CUSTOMER DEALSDeji displayed a tricky head movement and slipped punches, but failed to counter when it resumed.
Although Wassabi did not have any real technique, he was more persistent than his British counterpart.
Deji's fans at Wembley Arena were disappointed that he won a split-decision.
31-year-old Wassabi said, "I didn’t realize how difficult it was going to become." These people love their family."
Deji was then told: "Look man. I love you bro. All of the things from the past are gone.
Deji, whose brother KSI cheered him on from ringside was determined to never fight again if he lost.
The now-0-3 ex-gamer said: "I guess that I think too much when boxing. I don't punch well enough.
"Alex did well, I can't dispute that. We are grateful to everyone who came out.
Deji, 25, asked his fans if they would like to see him fight again. This was followed by a cheer before Wassabi and Deji shook hands for a rematch.
Maybe it will be Deji's fourth chance at fortune.
