Joseph Duffy has five losses against five opponents on his MMA record. For a list of Duffy's best fights, refer to "Best fights of Joseph Duffy".
On July 19, 2020 Joseph Duffy faced off against Joel Álvarez in a lightweight bout at age 32. He was coming in with a record of 16-5 (14), and Álvarez was 27 years old and with a record of 16-2 (16). Duffy lost the fight via 1st-round submission.
On March 16, 2019 Joseph Duffy faced off against Marc Diakiese in a lightweight bout at age 31. He was coming in with a record of 16-4 (14), and Diakiese was 26 years old and with a record of 12-3 (7). Duffy lost the fight via 3-round unanimous decision.
On November 4, 2017 Joseph Duffy faced off against James Vick in a lightweight bout at age 29. He was coming in with a record of 16-3 (14), and Vick was 30 years old and with a record of 11-1 (7). Duffy lost the fight via 2nd-round TKO.
On January 2, 2016 Joseph Duffy faced off against Dustin Poirier in a lightweight bout at age 27. He was coming in with a record of 14-2 (13), and Poirier was 26 years old and with a record of 18-4 (15). Duffy lost the fight via 3-round unanimous decision.
On October 1, 2011 Joseph Duffy fought Ivan Musardo in a lightweight title fight for the Cage Warriors Championship title. Duffy was 23 years old and with a record of 10-1 (9). Duffy lost the fight via 4th-round submission.
