[9] Lamas graduated with a degree in exercise science from Elmhurst College in 2005, where he was a member of the men's wrestling team and earned All-American honors at the NCAA Division III Men's Wrestling Championships at 157 lbs.
Lamas returned to Elmhurst after graduation to serve as the assistant men's wrestling coach.
[10] Lamas won the ISCF North Central Regional Title on April 26, 2008, in Loves Park, Illinois, US when he defeated Cal Ferry via Guillotine Choke at 4:50 of round 4.
[11] Lamas controlled Palaszewski with superior wrestling and scored with excellent ground-and-pound to win a unanimous decision.
[21] In October 2010, World Extreme Cagefighting merged with the Ultimate Fighting Championship.
[35] However, on June 14, it was announced that Jung had been pulled from the Lamas bout and would replace an injured Anthony Pettis to face José Aldo on August 3, 2013, at UFC 163.
[37] The title fight against José Aldo eventually took place on February 1, 2014, as the co-main event of UFC 169.
[38] It was revealed during the UFC countdown show that Lamas received his black belt in Brazilian jiu-jitsu during his training camp leading up to the bout.
[42] After dropping Bermudez with a jab, Lamas was able to secure a guillotine choke and earn the first round submission victory.
[43] Lamas faced Chad Mendes on April 4, 2015, in the main event at UFC Fight Night 63.
[45] Lamas faced Diego Sanchez on November 21, 2015, at The Ultimate Fighter Latin America 2 Finale.
[52][53] Lamas was quickly rescheduled and returned to face Charles Oliveira on November 5, 2016, at The Ultimate Fighter Latin America 3 Finale.
[55] Lamas won the fight via submission in the second round and was awarded a Performance of the Night bonus.
[58] However Jung pulled out of the fight in early June citing a knee injury.
[61] Lamas was scheduled to face José Aldo on December 16, 2017, at UFC on Fox: Lawler vs. dos Anjos.
[62] However, Aldo was pulled from the bout in favour of a rematch with Max Holloway two weeks earlier at UFC 218, replacing an injured Frankie Edgar.
[74] However, on April 9, Dana White, the president of UFC announced that this event was postponed to a future date.