Veselin Topalov — Vladimir Kramnik
The most controversial game in modern championship history — and no chess was played. Topalov's manager Silvio Danailov had submitted a formal complaint to the FIDE Appeals Committee citing over 50 bathroom visits by Kramnik during the first four games, implying the use of computer assistance. The committee ruled to lock Kramnik's private bathroom and replace it with a shared facility. Kramnik refused to play under these changed conditions as a matter of principle and forfeited the game. The point was awarded to Topalov; Toiletgate had engulfed the match.
No chess was played in Game 5. Topalov's manager Silvio Danailov submitted a formal complaint citing over 50 bathroom visits — a figure disputed by Kramnik's team — and requesting investigation into possible computer assistance.
The FIDE Appeals Committee's ruling to lock Kramnik's private bathroom mid-match was widely condemned as a violation of established playing conditions; Kramnik had been guaranteed a private restroom in his contract.
Kramnik announced he would continue the match only after the original conditions were restored — which they ultimately were for Game 7 — but Game 5's forfeit stood, shifting the score to 3–2 for Topalov.