Logan Paul has vowed to contest the decision that saw him lose his grudge match to YouTube rival KSI on the judges' scorecards.
KSI walked away with a split decision win after six rounds of boxing at the Staples Center in Los Angeles.
The Briton looked the more dangerous of the two but Paul finally broke through his defences mid-way through the fourth round with an impressive uppercut.
KSI - real name Olajide Olayinka Williams Olatunji - took a knee as a result of the shot, but with his opponent already on the mat, Paul landed another blow that left the other man visibly dazed.
Referee Jack Reiss scored the original knockdown for Paul, but having spotted the infringement, also took two points for hitting his opponent on the back of the head while he was down.
That decision proved pivotal with Paul losing by the narrowest of margins as KSI got the 57-54, 56-55, 55-56 win on the judges' scorecards.
After a heated build-up, Paul initially paid tribute to KSI, describing the Watford man as 'one of the toughest people I know.'
He then insisted however he would contest the judges' ruling and take the decision to a boxing commission.
Paul told Sky Sports: "Fair play to KSI. You are one of the toughest people I know.
"There's respect here. All the talk, It’s all for selling and I wish you the best.
"I felt more calm this year but I had two points taken away from me and is the reason I lost tonight.
"I’d love to fight KSI again - these are the best moments of my life. The more I practise in the box the more I feel comfortable.
"You’ll definitely see me in the ring again. But I am going to the commission about the decision."
Paul would register any complaints with the California State Athletic Commission who licensed Saturday's fight.
