In 2006, Pešta started training :simple:Musado|Traditional Musado under the leadership of Vít Skalník. Traditional Musado is the civilian version of Musado, the close quarters combat system used by the Military of the Czech Republic. In 2008, he started training MMA under the leadership of Jiří Vesecký in the gym in Příbram, Bohemia. Pešta moved to Prague to study at university and to pursue MMA career. In Prague, he began training in Penta Gym. He began amateur fighting at age of 18 and made his professional MMA debut in 2010. His last fight in GCF was with longtime GCF Heavyweight Champion Lukáš Ťupa for the GFC Heavyweight Championship on December 7, 2013 at GCF 26: Fight Night. Pešta won in the first round by his signature move, strikes from the mounted crucifix position and he became the new GCF Heavyweight Champion and #1 in Czech heavyweight rankings.
Ultimate Fighting Championship
Pešta became internationally well known for his website, . In February 2014, Pešta was offered a contract with the UFC. Pešta made his debut against face fellow newcomer Ruslan Magomedov on May 31, 2014 at UFC Fight Night 41. He lost the fight via unanimous decision. For his second fight with the promotion, Pešta faced touted newcomer Konstantin Erokhin on January 24, 2015 at UFC on Fox 14. Pešta won the fight by unanimous decision. Pešta faced Derrick Lewis on October 3, 2015 at UFC 192. He lost the fight via TKO in the third round. Pešta faced Marcin Tybura on August 6, 2016 at UFC Fight Night 92. He lost the fight via head kick KO in the second round. Pešta was expected to face Damian Grabowski on January 15, 2017 at UFC Fight Night 103. However, Grabowski pulled out of the fight in late December for undisclosed reasons and was replaced by Alexey Oleynik. He lost the fight via submission in the first round. In May 2017, Pešta was released from the company.
He signed a contract with Fight Nights Global in the second part of year 2017 after one match at home organization XFN.
Personal life
Pešta's signature move, the mounted crucifix position, was nicknamed/called "Bába pod kořenem " by his fans, after the famousCzech TV Nova's about an elderly woman who gets stuck for 11 hours under the root of a tree overnight, 50 metersaway from her rented hut in the forest and her friends. Poor Honza, Pešta's Czech nickname, is a Czech fairy talehero, similar to the EnglishJack, the GermanHans or the Russian Ivan.