TOKYO:  Japan's Shinsuke Yamanaka successfully defended his World Boxing Council bantamweight title for the eighth time on Thursday with a ferocious seventh-round knockout of Argentine Diego Santillan.

The 32-year-old Yamanaka uncoiled a venomous left to send the South American sprawling 36 seconds into the seventh in Osaka, having softened the challenger up in the previous rounds in a one-sided bout.

Santillan, five years the champion's junior, was bloodied and bruised well before Yamanaka's brutal coup de grace as he lost for the first time in 24 professional fights.

"I knew if I stayed patient I'd knock him out," Yamanaka told reporters after improving his record to 23 wins, 17 by knockout, with two draws.

The winner then insisted he was ready for a big pay-day.

APP