OpenAI meets Musk's Grok in AI chess tournament: Who won?

ChatGPT-maker OpenAI has battled Elon Musk’s Grok in the first-of-its-kind three-day chess tournament.

OpenAI’s o3 Large Language Model (LLM) defeated xAI's model Grok 4 in an impressive 4-0 victory in the final of the Google-owned platform Kaggle AI Exhibition Tournament, held on Thursday between August 5th-7th, according to The Independent.

Grok reportedly made a series of mistakes in the finale, including losing its queen “repeatedly.” OpenAI’s model, on the other hand, achieved an average accuracy rate of 12 games above 91%.

“Up until the Semifinals, it seemed like nothing would be able to stop Grok 4 on its way to winning the event,” Pedro Pinhata, a writer for Chess.com, said.

“But the illusion fell through on the last day of the tournament. The chatty o3 simply dismantled its mysterious opponent with four convincing wins. Grok's play was unrecognizable, blundering soon and often. And for the most part, o3 showed no mercy,” Pinhata adds.

Sam Atman and Elon Musk previously co-founded OpenAI before Musk left to pursue his own endeavours with xAI.

Google's model Gemini claimed third place in the tournament, beating o4-mini with a score of 3.5-0.5.

Prior to the finals, Musk posted on X: “@xAI spent almost no effort on chess.”

This is a side effect btw. @xAI spent almost no effort on chess. https://t.co/p18DFFn35A

undefined Elon Musk (@elonmusk) August 5, 2025

Eight LLMs participated in the tournament from Anthropic, Google, OpenAI, xAI, as well as Chinese developers DeepSeek and Moonshot AI (which were both eliminated early in the quarterfinals),

Such competitions are commonly held by developers to test their models in various areas, including reasoning and coding. Typically, complex rule-based, strategy games are opted for to see how effective a model is in learning to achieve the desired outcome.