John Ruiz vs. Nikolai Valuev was a professional boxing match contested on 17 December 2005, for the WBA heavyweight championship.

[1] After reversing his short lived retirement following his defeat at the hands of James Toney was changed to a non contest, John Ruiz agreed in October 2005 to face the undefeated Nikolai Valuev, who had just won a close and disputed title eliminator with Larry Donald.

However Valuev managed to rock Ruiz with a left in the eighth and edged the final round with right-left combination that wobbled the American.

Ruiz's long-time manager, Norman Stone, who had grabbed the belt and yelled insults at the Valuev camp following the decision, declared that they would also formally petition the WBA.

Wilfried Sauerland, the manager who rescued Valuev's career from obscurity two years earlier, angrily countered that the fans had booed because Stone's in-ring behavior had agitated them.