Chiasson started mixed martial arts at the age of 19, after being bed-ridden for three and one-half weeks recovering from a car accident to get back the fitness level she once was when she was a softball player in high school. After attending some Krav Maga classes at the martial arts gym, she was attracted to the physical aggressiveness and the tough mental side of the combat sport and started teaching Krav Maga after one year of training. Chiasson transitioned to mixed martial arts, training under Mushin MMA and Mid City MMA, as Krav Maga is not a competition combat sport. Not long after she started training mixed martial arts, she started competing professionally.
Chiasson started her professional MMA career since 2017 and amassed a record of 2-0, fighting under Invicta Fighting Championships and Cage Warrior Championship, prior participated in UFC TV mma competition series which she was subsequently signed by UFC after the show.
The Ultimate Fighter
In August 2017, it was announced that Chiasson was one of the fighters featured on The Ultimate Fighter 28 UFC TV series. Chiasson was the second pick of the featherweight fighters by coach Kelvin Gastelum. In the quarter-finals, she faced Larissa Pacheco. She won the fight via a technical knockout in round one. In the semi-finals, Chiasson faced Leah Letson She once again finished the bout by way of knockout in round one. This win secured Chiasson a spot in the finals against Pannie Kianzad.
Chiasson made her promotional debut on November 2, 2018 on. against Pannie Kianzad. She won the fight via a rear-naked choke submission in round two and winning the Ultimate Fighter women's featherweight tournament. She made her Bantamweight debut on March 2, 2019 at UFC 235 against Gina Mazany. She won the fight via TKO in the first round. On February 10, 2019, Chiasson replaced an injured Leah Letson and faced Sarah Moras on May 4, 2019 at. Chiasson won the fight via technical knockout in the second round. This win earned her the Performance of the Night award. Chiasson faced Lina Länsberg on September 28, 2019 at UFC on ESPN+ 18. She lost the fight via unanimous decision. Chiasson was scheduled to face Nicco Montaño on February 15, 2020 at UFC Fight Night 167 However, Montaño was forced to pull from the event due to injury and she was replaced by Shanna Young. Chiasson won the fight by unanimous decision. Chiasson is scheduled to face Sijara Eubanks on September 5, 2020 at UFC Fight Night 177.
