After scoring back-to-back pinfall victories over top contender Hirooki Goto and Tetsuya Naito on December 11 and 12, Tanahashi was granted a shot at the IWGP Heavyweight Champion Satoshi Kojima at Wrestle Kingdom V in Tokyo Dome. At the event on January 4, 2011, Tanahashi defeated Kojima to win the IWGP Heavyweight Championship for the fifth time. On February 20 at The New Beginning, Tanahashi made his first successful defense of the title, defeating Kojima in a rematch. Tanahashi went on to successfully defended the title against New Japan Cup winner Yuji Nagata on April 3 and Shinsuke Nakamura on May 3. In May 2011, Tanahashi took part in the Invasion Tour 2011, New Japan's first ever tour of the United States, during which he successfully defended the IWGP Heavyweight Championship against Charlie Haas on May 14 in New York City.