Freire's achievements in Bellator led many to believe, including Pettis, that he is the greatest fighter to ever grace the promotion.
He is a record three-time featherweight champion and became the second person in Bellator history, after Ryan Bader, to hold belts simultaneously in two divisions when he beat Michael Chandler for the lightweight title in 2019.
In attempting to become the first triple champion in a major MMA promotion, Freire was dropping down to bantamweight for the first time and described the 10-pound weight drop as "the easiest of his career".
Pettis, meanwhile, was competing for the first time in over 18 months - the longest lay-off of his career - after suffering a serious knee injury which required surgery.
Pettis said facing Pitbull, coupled with his time out injured, led him to doubt himself pre-fight.
"I ain't going to lie. I was telling my girl like, 'hey, if I lose to anybody, it's okay to lose to Patricio Pitbull, he's a legend'," said Pettis in his post-fight press conference.
"I didn't think I was going to lose, I just had battles in my mind. I was nervous, scared, all of the above. Eighteen months off from competing, so I kind of forgot how all this felt."
During his time on the sidelines, American fighter Mix, 29, claimed the interim title after winning Bellator's Bantamweight Grand Prix tournament, with many pundits and fans expecting a unification bout with Pettis upon his return.
Bellator opted for Freire, however, with Pettis describing the bout as an opportunity to add to his legacy.
Freire was the first ever challenger in a Bellator champion versus champion bout to drop down a division, and much of the pre-fight discussion was how the weight cut would affect his performance.
The difference in size wasn't too noticeable between the fighters, but Pettis carried the faster speed which proved crucial in victory.
After a timid first round with both fighters landing leg kicks from distance, Pettis started to open up in the second, landing body-shot combinations and a flamboyant spinning wheel kick which hurt Freire.
Pettis continued to out-strike Freire as blood poured from a cut above the Brazilian's left eye, and although Freire landed a couple of takedowns, he was unable to deal any damage.
Cheered on by brother and former UFC champion Anthony at cageside, Pettis safely navigated the end of the fight, countering a more urgent Freire with swift combinations in the final round as the Brazilian looked for a knockout.
After the bell rang, both fighters bowed to each other before Freire sunk to his knees in contemplation upon hearing he had lost.
"It was an intense day for me today, pacing back and forth, sweating non-stop," said Pettis.
"I was definitely nervous. To get past that and have these battles with myself, I think that's the thing that makes me perform my best."
ncG1vNJzZmivp6x7o67CZ5qopV%2BovbC%2B02ikorCVmXqurdGtoJqkXZa%2Ftb%2BOb2xya2ZugHU%3D