Carl Frampton announced his retirement in the ring after being stopped by Jamel Herring in the sixth round of their WBO super-featherweight contest.
The Belfast man was bidding to become Ireland's first three-weight world champion.
Herring dropped Frampton, 34, a round earlier before another left uppercut in the sixth sent Frampton to the canvas.
Amid a flurry of shots and little defence, Frampton's corner threw in the towel.
"I said before I would retire if I lost this fight and that's exactly what I'm going to do," an emotional Frampton said in the ring.
"I just want to dedicate my life to my family now. Boxing has been good to me, it's also been bad to me.
"The last few years with these boys [trainers Jamie Moore and Nigel Travis], have been the best of my career.
"I just want to go home to my beautiful wife and kids and that's it."
Defeat draws curtain on Frampton's career
After losing to Josh Warrington in December 2018, Frampton seriously considered retiring but opted to continue in pursuit of another world title, firm in the belief he still had that level of performance in him.
The nature of the loss to Herring, given his assertion prior to the fight that such a result would signal an end to his career, has left Frampton with no doubt that the time is right to hang up his gloves.
Before the first knockdown, Herring was firmly in control of the contest having used his jab and seven-inch reach advantage to take the first three rounds.
Although not rocked, Frampton was already left with considerable ground to make up and did get to work in the fourth as a cut formed over Herring's right eye.
However just as the Northern Irishman looked to be working his way back into the contest he walked onto a left hand midway through the fifth as the pendulum swung back in Herring's favour.
A wonderful left uppercut from Herring in the next round saw Frampton go down again, and although he did get back up, was unable to stop Herring closing in and securing the win.
The decision of trainer Moore to throw the towel in came as little shock, with a dazed Frampton stopped for the first time in a 31-fight professional career.
For Herring, it was an impressive third defence of a title he has held since May 2019. The southpaw was far more impressive in Dubai than he was in his last outing, where his lukewarm performance had galvanised Frampton fans looking ahead to their long-awaited showdown.
'He is one of my favourite fighters' - what they said
WBO super-featherweight champion Jamel Herring: "My last outing wasn't my best. People doubted me. They called me everything in the book. Even with the cut, I wasn't going to give up. I wasn't going to give in. I wasn't going to quit.
"He [Frampton] is honestly one of my favourite fighters. I'm honoured to be able to share the ring with him. He's a two-divisional world champion.
"He's done great things for the sport of boxing and it was just an honour."
WBA and IBF light-welterweight world champion Josh Taylor on Channel 5: "Carl misses his kids and his wife, and he has spent a whole lot of time away from them.
"I remember when I was in the same set-up as him he was always away from his kids, he has spent these last five or six years away from them and has missed them growing up. I think he'll keep his promise to his wife and he'll go and enjoy his family life now."
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Frampton's wife Christine thanks fans after the fight
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