Gsbt

Floyd Mayweather Jr. will retire a perfect 50-0 -- and Conor McGregor made him work for it. McGregor's first boxing match was a heckuva show -- the 29-year-old mixed martial-arts superstar acquitted himself beautifully on Saturday night in Las Vegas, hitting Mayweather more than the champ is used to -- but one of the 40-year-old Mayweather's powerful right-hand jabs round dazed the Irishman badly in the 9th, and Mayweather quickly took advantage. SEE ALSO:  Floyd 'Crypto' Mayweather is totally into cryptocurrencies Mayweather pressed the attack straightaway in the 10th; McGregor, looking totally gassed, had nothing left, and as Floyd's punches began landing more fiercely, veteran referee Robert Byrd called it. Mayweather would win his last fight in a knockout. McGregor went toe-to-toe with Mayweather in early rounds, landing straight-ahead jabs, counterpunching well and overall being more active and aggressive than his veteran opponent. Mayweather kept ducking,