Strawweight world titleholder Wanheng Menayothin knocked out mandatory challenger Leroy Estrada in the fifth round of a one-sided fight to reach 50-0 on Wednesday in Nakhon Ratchasima, Thailand.
Menayothin (50-0, 18 KOs) scored five knockdowns as he matched the same glossy mark that Floyd Mayweather retired with after knocking out Conor McGregor in the 10th round in August, though other boxers have begun their careers with longer winning streaks.
Menayothin, 32, of Thailand, retained his 105-pound world title (boxing's smallest division) for the ninth time since winning it in 2014 as he took apart Estrada (16-2, 6 KOs), 23, of Panama, who had his four-fight winning streak stopped.
Fighting outdoors, Menayothin dished out a tremendous amount of punishment to Estrada, whom he dropped twice in the third round, the first one coming from a clean right hand that sent him to his backside early in the round and then again with a sweeping right hand that put him on his back with about 45 seconds left in the round.
Menayothin scored two more knockdowns in the fourth round, first with a bruising three-punch combination and then with two clubbing right hands that dropped him to his knees.
Menayothin finished Estrada in the fifth round, battering him into the ropes and nailing with several punches, including a right uppercut that rocked his head back and sent him to the canvas for the fifth time as referee Jay Nady waved off the fight without a count.