Jaime Munguia defeated Takeshi Inoue by unanimous decision to retain his WBO junior middleweight title.
Mexican boxer Munguia held off previously unbeaten Inoue after 12 brutal rounds at the Toyota Center in Houston on Saturday.
Munguia (32-0, 26 KOs) was made to earn the victory, with judges scoring the fight 120-108, 120-108 and 119-109.
The 22-year-old Munguia's power proved too much for Japanese opponent Inoue, who dropped to a 13-1-1 record.
"I came to give everything and I want to congratulate my rival, who left everything on the ring," Munguia said in his post-fight interview.