Growing up in Ansonia, Connecticut, Ballester studied Bruce Lee tapes and eventually channeled his love of doing backflips, handstands and scaling walls into backyard wrestling.

Fox worked for a brief time at Big Y World Class Market, a grocery store, with TJ Guerrero, that he left shortly after finding popularity in wrestling.

[9][10] Ballester eventually adopted the ring name "AR Fox", feeling that due to his small size, he needed to "outfox" his opponents to gain an advantage.

[8] Ballester, as AR Fox, made his debut for Combat Zone Wrestling (CZW) on February 13, 2010, losing to Aaron Arbo in an "Opportunity Knocks" three-way match, which also included Unbreakable Andy.

[1] On September 10, Fox defeated Alex Colon, Facade, Ricochet, Ruckus and tHURTeen in to win the Chris Cash Aerial Assault ladder match and become the number one contender to the CZW World Junior Heavyweight Championship.

After debuting his new finishing maneuver, Lo Mein Pain, Fox had the match won when CZW owner D. J. Hyde entered the ring and hit him with a lariat, leading to Cole retaining his title.

[36] On November 10, Fox made his first defense of the Wired TV Championship, defeating Lucky 13, Rich Swann and Shane Strickland in a four-way match.

[37] On December 8 at Cage of Death XIV, Fox successfully defended the CZW Wired TV Championship against a surprise opponent, the returning Robert Anthony.

[41][42] On March 31, Fox successfully defended the title against Flamita at a Desastre Total Ultraviolento (DTU) event in Mexico City.

[45][46][47] On May 11, Fox teamed with Athena in the 2013 Queen and King of the Ring tournament, which CZW co-promoted with the Women Superstars Uncensored (WSU) promotion.

[48][49] On September 14, Fox lost the Wired TV Championship to Alex Colon in a four-way ladder match, which also included Andrew Everett and Shane Strickland.

[53][54] On November 20, 2010, Fox made his debut for the Evolve promotion, defeating Rich Swann, Scott Reed and Tony Nese in a four-way match.

[55] On January 29, 2011, Fox made his debut for Evolve's close affiliate, Dragon Gate USA, losing to Sami Callihan in a six-way match.

[64][65][66] Back in Dragon Gate USA on September 10, Fox teamed with the debuting veteran wrestler Sabu to defeat Cannon and Sanchez in a No Disqualification match.

[80] On November 4, Fox received another shot at the Open the Freedom Gate Championship in a four-way elimination match with champion Johnny Gargano, Akira Tozawa and Ricochet.

[81] On April 5, 2013, Fox defeated Jon Davis, Ricochet and Sami Callihan during a one-night single-elimination tournament to become the inaugural Evolve Champion.

[89] On November 16, Fox made his fifth successful defense of the Evolve Championship in a four-way match against Fire Ant, Mr. Touchdown and Shane Strickland.

[110] On August 30, Fox returned to PWG to take part in the 2013 Battle of Los Angeles, but was eliminated from the tournament in his first round match by Roderick Strong.

[111] From October 3 to 6, Fox took part in Westside Xtreme Wrestling's (wXw) 2013 World Triangle League, which also marked his debut for the German promotion.

[112] On September 20, 2014, Fox made his debut for Chikara, entering the Rey de Voladores tournament and losing to The Great Sanada in a four-way match, which also included Amasis and Orlando Christopher.

[114] On July 10, Fox made his debut for Global Force Wrestling (GFW), defeating Aaron Draven and Chuck Taylor in a three-way match.

Fox also makes sporadic appearances in AEW's sister promotion Ring of Honor (ROH), usually teaming with Top Flight in trios matches against various opponents.

Following a loss to Orange Cassidy in a match for the AEW International Championship on the July 26, 2023 episode of Dynamite, AR Fox joined the Mogul Embassy after helping Swerve Strickland defeat Darby Allin, turning heel in the process.

On the August 23 episode of Dynamite, Strickland kicked Fox out of Mogul Embassy after the duo were defeated by Allin and Nick Wayne in a tag team match, turning face once again in the process.