Floyd Mayweather defeated Andre Berto at the MGM Grand in Las Vegas to equal Rocky Marciano's legendary 49-0 unbeaten record.
'Money' Mayweather outclassed his opponent, claiming a routine 12-round decision in what, according to the champion and his camp, will be his last fight.
"You've got to know when to hang it up," Mayweather said to pay-per-view network Showtime, "... and I think it's about time for me to hang it up.
"I'm knocking at the door now. I'm close to 40 years old. Been in this sport 19 years. I've broken all the records. There's nothing more to prove."
Career in pictures: Floyd Mayweather
Despite the retirement talk, it is widely expected that Mayweather, who is estimated to have made around $700m during his career, will fight again in a landmark 50th bout, which will also present him with the opportunity of breaking Marciano's record.
The victory over Berto came after a testing week for the Mayweather camp, after claims emerged that the fighter used intravenous therapy to rehydrate himself after weighing-in before his super-fight against Manny Pacquiao in May. The treatment is prohibited by the World Anti-Doping Agency.
Mayweather has denied any wrongdoing and the United States Anti-Doping Agency confirmed he had been granted a Theraputic Use Exemption, allowing him to receive the treatment.
George Groves in action against Badou Jack at the MGM Grand
On last night's undercard, British super-middleweight George Groves failed to claim a world title at his third attempt, falling on the wrong side of an agonising split decision in his bout with Badou Jack
The Hammersmith fighter recoverd from a knock down in the opening round to take the WBC super-middleweight champion the distance, only for the judges to score 115-112, 113-114, 116-111 in favour of Jack.
