ネットバトル大会を控え、特訓に余念のない熱斗たち。一方でWWWの面々も大会に出場を決め、悪事を企んでいた。大会当日の朝、日暮のナビ、ナンバーマンがカスタマイズのミスにより暴走、それを止める為に奔走する熱斗たちだが大会に遅刻しそうになる。 が、やいとの自家用機のおかげでなんとか間に合い、第1試合デカオ&ガッツマンの試合が始まる。
Everyone is training really hard for the approaching N1 Grand Prix, even the World Three! Higure has upgraded Numberman to such a high level that he loses control and begins causing mayhem all throughout the city! He rushes to Netto and co. and pleads for help, but Numberman is very powerful now! Tohru reappears to send his navi, Iceman, to help... but Numberman is still too strong! The day is eventually saved by a mysterious, skeleton navi, but he escapes soon after. With that problem solved, everyone rushes to the tournament; Dekao's match is first! He takes an easy win, and Netto becomes stoked about the future of this tournament. English version title - The N1 Grand Prix!