The 23 year-old, who claimed the WBC title at 105lbs in just his seventh bout, overcame a stubborn challenge from Yaegashi, 29, to take the WBA title and place himself in the frame for a place in the WBN P4P Top 50 in the near future.
Yaegashi fought hard when hampered by a swollen eye, but eventually compatriot Ioka’s tenacity shone through and the judges gave him a unanimous decision with cards of 115-113 (twice) and 115-114.
