Analysis of information sources in references of the Wikipedia article "IWGP Heavyweight Championship (IGF)" in English language version.
The IWGP 3rd Belt
Angle went on to also defeat Brock Lesnar in Tokyo for the IWGP belt
In the usual Inoki manner, the debut show was followed by great controversy. In the run-up to the show, Inoki already announced that she wanted to fight out the IWGP Heavyweight Title in the main event between Lesnar and Angle. Brock Lesnar was the holder of the title until July 2006, but then refused to lose a title match against Hiroshi Tanahashi, whereupon New Japan (owner of the IWGP trademark) revoked the title. However, Lesnar refused to return the title and simply kept it to himself. After announcing the IGF main event, Inoki said Lesnar was still the champion and that the title would be at stake in the match. The NWA governing body recognized Lesnar (and then Angle, who won the debut show title) as the NWA Japan Champion
Angle went on to also defeat Brock Lesnar in Tokyo for the IWGP belt