Shinsuke Yamanaka, right, improved to 22-0 with 16 knockouts.
Tokyo, Japan (SportsNetwork.com) -
WBC bantamweight champion Shinsuke Yamanaka remained unbeaten with a unanimous decision over Suriyan Sor Rungvisai on Wednesday.
Yamanaka knocked Rungvisai down in each of the seventh, eighth and ninth rounds. He won easily by scores of 116-108, 115-109 and 114-110, but failed to produce a knockout for the first time in seven bouts.
It was the 32-year-old Japanese southpaw's seventh successful title defense. He improved to 22-0 with 16 knockouts.