Rex Raptor and Weevil Underwood's Duel was the final Duel of the the Japanese National Duel Monsters Championship in the Yu-Gi-Oh! anime. In is based on a Duel from the manga.
The finalists were Weevil Underwood from East Japan and Rex Raptor from West Japan, aged 14 and 15 respectively at the time. One of them defeated Mako Tsunami in the semifinals.
Rex Summoned "Two-Headed King Rex" and Weevil countered with "Basic Insect".
"Two-Headed King Rex" attacked "Basic Insect", but Weevil activated "Vortex", negating the attack.
Weevil equipped "Basic Insect" with "Level 5 Laser Cannon" ("Basic Insect": 500 → 2000 ATK).
"Basic Insect" attacked and destroyed "Two-Headed King Rex" (Rex: 0 LP), winning the Duel for Weevil.
Maximillion Pegasus presented Weevil was the trophy for winning the tournament and invited him to take part in his upcoming Duelist Kingdom tournament.