From Bulbapedia, the community-driven Pokémon encyclopedia.
The Pokémon Number One Grand Prix, known better as the P1 Grand Prix is a special Pokémon battle tournament held especially for Template:Type2 Pokémon. Each Pokémon Trainer who enters chooses only one Pokémon and engages in a series of one on one battles. The prize is a golden championship belt. It has only appeared in The Punchy Pokémon, although it is referenced in A Tyrogue Full of Trouble.
Ash's Primeape and Brock's Geodude were both entered into the P1 Grand Prix, with Geodude being knocked out by Giant's Hitmonlee under Jessie's ownership, and Primeape winning the tournament and the belt.
The P1 Grand Prix's definition of "Fighting-type" Pokémon for the tournament seems to be based on one from the Pokémon Trading Card Game rather than the Pokémon games or Pokémon anime, as Ground- and Template:Type2 Pokémon can apparently be entered as well. In the TCG, Fighting, Ground, and Rock are all considered a single type.