Katsuyori Shibata
On April 9, 2017, Japanese wrestler Katsuyori Shibata headbutted Kazuchika Okada during their match at Sakura Genesis 2017. The headbutt was so hard that it caused Shibata to start bleeding from the forehead. After the match, Shibata collapsed backstage, from where he was taken to the hospital and diagnosed with a subdural hematoma.