Fili made his professional debut on December 12, 2009 against Anthony Motley. Fili won the fight via TKO and won his next three fights via TKO as well. Fili suffered his first loss, by knee injury, against Strikeforce vet Derrick Burnsed.
Fili bounced back from the loss winning his next 8 fights including a win over Strikeforce veteran Alexander Crispim.
Fili made his promotional debut on October 19, 2013 at UFC 166 against Jeremy Larsen. Fili, who was in the middle of a training camp for a welterweight bout in another promotion, took the featherweight fight on short notice (two weeks) to replace an injured Charles Oliveira. The bout was contested at a catchweight, as Fili was unable to make the required weight. Fili won the fight via TKO in the second round.
Fili faced Max Holloway on April 26, 2014 at UFC 172. He lost the back-and-forth fight via submission in the third round.
Fili was expected to face Sean Soriano on September 5, 2014 at UFC Fight Night 50. However, Fili was forced from the bout with an injury and replaced by Chas Skelly.
Fili faced Felipe Arantes on October 25, 2014 at UFC 179. He won the back and forth fight via unanimous decision. Both fighters in the duration of the bout showed nice scrambles, But Fili showed good wrestling, securing five takedowns on Arantes which was enough for the judges to score the win for Fili.
Fili faced Godofredo Pepey on March 21, 2015 at UFC Fight Night 62. He lost the fight via submission in the first round.
Fili was expected to face Clay Collard on September 5, 2015 at UFC 191. However, Fili was forced out of the bout with injury and replaced by Tiago Trator.
Fili faced Gabriel Benítez on November 21, 2015 at The Ultimate Fighter Latin America 2 Finale. He won the fight via knockout in the first round and also earned a Performance of the Night bonus.
Fili faced Yair Rodríguez on April 23, 2016 at UFC 197. Fili lost the fight via knockout in the second round.
Fili faced Hacran Dias on October 1, 2016 at UFC Fight Night 96, filling in for an injured Brian Ortega. He won the fight via unanimous decision.
Fili was expected to face Doo Ho Choi on July 29, 2017 at UFC 214. However Choi pulled out of the fight and was replaced by promotional newcomer Calvin Kattar. Fili lost the fight by unanimous decision.
Fili is expected to face Artem Lobov on October 21, 2017 at UFC Fight Night 118.