Holtzman was born in Knoxville, Tennessee and spent his childhood in Fountain City. He attended Central High School, where he played football and baseball. During high school, he also played ice hockey with the Knoxville Amateur Hockey Association. After high school, Holtzman attended Hiwassee College, where he played baseball and earned an associate degree in Business Administration. He transferred from Hiwassee to the University of Tennessee, where he played club hockey and earned a bachelor's degree in Sociology. In 2008-09, Holtzman enjoyed a brief stint playing for the Knoxville Ice Bears.
Holtzman began his professional mixed martial arts career in 2009. He compiled an undefeated amateur record of 4-0, with his final match earning him a contract with the Xtreme Fighting Championships. In his professional debut, Holtzman defeated Brandon Demastes by rear-naked choke at in front of a home crowd in Knoxville, Tennessee. He would decidedly win his next two fights against Matt Metts and Chris Coggins each in the first round by KO/TKO stoppage respectively.
XFC Lightweight Title
Holtzman opened up 2013 with a win by unanimous decision against Jason Hicks in a title eliminating match at XFC 22: Crossing The Line. After his match with Hicks, Holtzman was expected to face, then XFC Lightweight champion, Nick Newell for the Lightweight belt. In May 2013, it was reported that Newell had refused to fight Holtzman. According to XFC president, John Prisco, Newell was hoping to face former UFC fighters in order to make his claim to move up into the UFC. Prisco, however, felt that Holtzman had "earned the right" to face Newell for the title. Since Newell refused to fight Holtzman, Prisco stripped Newell of his belt and paired Holtzman against John Mahlow to compete for the vacated Lightweight belt at. On June 14, 2013, Holtzman beat Mahlow by TKO in the second round to win the XFC Lightweight Title. Holtzman quickly had the opportunity to defend his title at, where he won by unanimous decision against Roger Carroll. After a hiatus due in part to a lack of reputable opponents and the XFC's focus on their new international partnerships, Holtzman secured a fight outside of the XFC against George Sheppard at the Premier Fighting Championships 9: Unstoppable. Holtzman would go on to win by unanimous decision.
Ultimate Fighting Championship
On August 14, 2014, Holtzman announced that he had signed a four-fight deal with the UFC. Holtzman made his promotional debut against Anthony Christodoulou on August 8, 2015 at UFC Fight Night 73. He won the one-sided fight via submission in the third round. In his second fight for the promotion, Holtzman faced Drew Dober on January 2, 2016 at UFC 195. He lost the fight by unanimous decision. Holtzman next faced Cody Pfister on July 13, 2016 at UFC Fight Night 91. Holtzman won the fight via unanimous decision. Holtzman faced Josh Emmett on December 17, 2016 at UFC on Fox 22. He lost the fight by unanimous decision. Holtzman next faced Michael McBride April 22, 2017 at UFC Fight Night 108. He won the fight via unanimous decision. Holtzman faced Darrell Horcher on December 9, 2017 at UFC Fight Night 123. He won the fight by unanimous decision. On January 25, 2018 Holtzman announced that he had signed a new, four-fight deal with UFC. Holtzman faced Alan Patrick on October 6, 2018 at UFC 229. He won the fight via knockout in the third round after dropping Patrick with a punch and eventually finishing the fight with elbows. Holtzman faced Nik Lentz on February 17, 2019 at. He lost the fight by unanimous decision. Holtzman faced Dong Hyun Ma on August 3, 2019 at UFC on ESPN 5. He won the fight via TKO due to a doctor stoppage between the second and third round as the swelling on Ma's right eye rendered him unable to continue. Holtzman faced Jim Miller on February 15, 2020 at UFC Fight Night 167. He won the back-and-forth fight by unanimous decision. The bout also earned Holtzman his first Fight of the Night bonus award. Holtzman is scheduled to face Beneil Dariush on August 8, 2020 at UFC Fight Night 174.
