Before the G1 Climax and even the IWGP Heavyweight Title, New Japan held an annual round-robin IWGP League. The first was won by American superstar, Hulk Hogan, when he KO'd Antonio Inoki in a well documented moment. The following year, Hogan faced the winner of a league in the tournament final, and Inoki scored his revenge there. Although the winner received a title belt, this was NOT the IWGP Heavyweight Title as we know it, but more of a prelude.

1983 (5/6/83 to 6/2/83)
1. Hulk Hogan [37]
2. Antonio Inoki [37]
3. Andre The Giant [36]
4. Big John Studd [25]
5. Killer Khan [24]
6. Kengo Kimura [21]
7. Akira Maeda [14]
8. El Canek [5]
9. Otto Wanz [5]
10. Enrique Vera [0]
Final: Hulk Hogan beat Antonio Inoki (21:27) by KO.

1984 (5/11/84 to 6/14/84)
1. Antonio Inoki [53]
2. Andre The Giant [49]
3. Riki Choshu [34]
4. Tatsumi Fujinami [33]
5. Dick Murdoch [30]
6. Masa Saito [26]
7. Adrian Adonis [25]
8. Masked Superstar [18]
9. Ken Patera [17]
10. Big John Quinn [10]
11. Otto Wanz [6]
12. Big John Studd [2]
Final: Antonio Inoki beat Hulk Hogan (22:39) by countout.