50. The Mystery Duelist, Part 1(過去からの挑戦 戦慄のゼラ)
Canon
An arcane fortune teller steals the Millennium Puzzle and Yuugi must defeat him in a Duel to win it back. Can Yuugi beat him all alone without the help of his friends or the spirit inside the puzzle? (Source: Yu-Gi-Oh! Wikia)
Aired on: 4/9/2001