Things You'll Need
Instructions
Obtain a Poliwag in Pokemon Fire Red or Leaf Green. You can find them in Viridian City, Route 24 or Fuchsia City. Use a Good Rod to fish in these areas.
Train Poliwag to level 25 so it will evolve into a Poliwhirl. Buy a Water Stone from Celadon City Department Store to use on Poliwhirl. The Water Stone will evolve Poliwhirl into a Poliwrath.
Connect your Gameboy Advance to a separate Gameboy Advance that has the Sapphire cartridge using a Game Boy Advance link cable.
Go inside any Pokemon Center and head upstairs. Talk to the third person behind the desk. From there you will save the game and enter the room where you will trade.
Trade Poliwrath to Sapphire in exchange for another Pokemon. After the trade Poliwrath should be in your party in Sapphire.