Pokémon Green Version (Japanese) - Rocket Boss Giovanni Battle #2

Once you reach the president’s office on the 11F of Silph Co., open the shutter and battle Giovanni for the 2nd time. For this round, he removes Onix. His replacements are Nidorino and Nidoqueen. You can easily take out the opposing Pokémon with Earthquake, a move from a TM26 received on the 10F in the building. After the battle, talk to the president and he will give you a Master Ball. A Master Ball will catch any Pokémon without fail.