Complex sentence: He challenged the WBA world minimumweight champion Yutaka Niida in Yokohama City, Japan and scored a technical knockout to win the title in 58 seconds of the fourth round on September 15,2008.
Split into simpler sentences: He challenged the WBA world minimumweight champion Yutaka Niida in Yokohama City, Japan. He scored a technical knockout and became a new WBA world minimumweight champion in 58 seconds of the fourth round on September 15,2008.