 In his ten years as executive vice president and chief content officer for the UFC, Zelaznik oversaw the organization's pay-per-view and digital business and was also tasked with growing the organization's presence in markets outside of the United States.During his tenure the UFC opened up markets in the UK, Brazil, Ireland, Germany, Sweden, Mexico, UAE, Japan, Korea, Philippines and Mexico

Zelaznik is created the UFC's own in-house digital streaming platform Fight Pass, which Inc. credits with "helping build UFC's content business into one of the most widely-available sports properties in the world".The UFC subsequently achieved a $4.025bn valuation - the largest-ever sports-industry acquisition, according to the New York Times - when it was sold by Zuffa LLC to Endeavor.