OpenAI's o3 model defeated Elon Musk's Grok 4 in the finals of an AI chess tournament, intensifying the rivalry between the two tech giants. The competition, held on Google's Kaggle platform, pitted everyday AI programs against each other, rather than chess-specific computers.

• OpenAI's o3 model remained unbeaten throughout the tournament.
• The tournament highlighted an ongoing rivalry between OpenAI and xAI, founded by Elon Musk.
• Despite early success, Grok 4 made numerous errors in the finals, surprising observers like Chess.com writer Pedro Pinhata and chess grandmaster Hikaru Nakamura.