The talented youngster, who had fought just 10 rounds prior to today's bout, took control of this one very early as he inflicted a cut on Matsui's left eye in the opening round.
The cut was a huge target for Hatanaka who looked sharp and accurate as he tagged at the cut with his jab. The cut worsened as the fight went on, and twice forced a doctors inspection in round 4.
The cut was clearly a growing issue for the fighter, and officials, but in the end it wasn't the key factor in the fight with Hatanaka hurting Matsui in round 5 and forcing the referee to stop the bout as Hatanaka began to unload.
This is a second straight loss for Matsui, who also lost in a Japanese Minimumweight title fight in December against champion Reiya Konish. It should be noted however that this is is only his second stoppage loss, with the other being an 8th round loss in 2016 to Tetsuya Hisada. Whilt that might sound terribe for Matsui it really does show how much promise Hatanaka has and how impressive today's win was.
(Image courtesy of boxmob.jp)