IWGPヘビー級王座
Wrestle Kingdom 8 was headlined by a "double main event", featuring Kazuchika Okada defending the IWGP Heavyweight Championship against Tetsuya Naito and Shinsuke Nakamura defending the IWGP Intercontinental Championship against Hiroshi Tanahashi. In the first of the main events, Okada made his seventh successful defense of the IWGP Heavyweight Championship against Naito, while the second main event saw Tanahashi defeat Nakamura to become the new IWGP Intercontinental Champion.