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Maycee Barber's goal of becoming the youngest champion in UFC history took a sizable step backwards on Saturday in the co-main event of UFC 258. Barber, a 22-year-old flyweight prospect, suffered her second straight defeat after Grasso (13-3) relied on slick counterpunching and an improved ground game to score a unanimous decision (29-28, 29-28, 29-28) inside the UFC Apex facility. 

Grasso (13-3) scored her second straight win since moving up to 125 pounds in what was the most impressive victory of her career to date. It's a victory made sweeter by the native of Mexico's ability to hold off a furious rally from Barber (8-2) in the final round. 

"I trained so hard for this fight," Grasso said. "I told you that I am working so, so hard. I want to evolve and show every fight that I am better and better. I know you know me as a striker, but I am working so hard on my grappling and I want to be a complete fighter."

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Barber saw her window continue to close in regards of her hopes of besting Jon Jones' mark of winning a UFC title at age 23. The native of Colorado proved unable to answer the majority of questions she faced coming in following a 13-month layoff and ACL surgery in the aftermath of her 2020 upset loss to Roxanne Modaferri. 

Aside from the heavy strikes and takedowns she landed in the final round, Barber was seemingly a step behind the 27-year-old Grasso throughout. Barber often feinted, but did so curiously from way too far outside to no avail. 

Barber also had trouble penetrating Grasso's high guard when she did get inside. That led to Grasso smothering Barber's punching power by repeatedly forcing her into a clinch and showed an improved grappling ability on the ground. Grasso fought off an armbar attempt late in Round 2, and went on to take Barber's back while nearly securing a choke before the final horn. 

After opening her UFC career with a 3-3 record in the loaded strawweight division, Grasso became unable to make the 115-pound limit and appears reborn in her new division.

"When I started fighting, I saw the strawweights and said that I want to be in that division, no matter what," Grasso said. "But obviously, it was becoming very hard to cut that much. My weight is my weight, and now I can build my muscles without that cut. My body is saying, 'Thank you, thank you Alexa.'"