In August 2015, a deal was reached for Povetkin to fight once beaten former world title challenger Mariusz Wach (31-1, 17 KOs) in Kazan, Russia 4 November 2015. Wach had previously gone 12 rounds with Wladimir Klitschko. The fight would be the main event of a packed Russian card that featured multiple world title fights. After the fight was announced, Povetkin spoke of his disappointment of not being able to land Wilder on the same date. Wach started off the fight with success, keeping the smaller Povetkin at range with his jab. But as the rounds went on, Povetkin was able to find his range and begin to push Wach around the ring with combinations on the inside. Towards the end of the fight, with both participants cut, Povetkin urged the referee stoppage as he deemed Wach, who was being hit at will essentially, unable to continue. On the morning of the fight, the WBC approved another voluntary defence for Wilder, which would likely take place in January 2016. This meant the potential Wilder vs. Povetkin fight would take place around May 2016. Wach allegedly only received 10% of his purse, due to his ongoing difficulties with his promoter Jimmy Burchfield. In December, it was reported that Wach failed a post-fight drug test.