Joseph Diaz losses
Over 14 years as a professional, Joseph Diaz has compiled a 34-10-1 (15) record, including 15 title fights across four weight classes. He has ten losses, three of them in title fights.
10. Joseph Diaz loses to Ashton Sylve via unanimous decision
On June 19, 2026 Joseph Diaz faced Ashton Sylve in a lightweight bout. Diaz was 33 years old with a record of 34-9-1, and Sylve was 22 with a record of 13-1. Diaz was on a 2-fight losing streak, while Sylve was on a 2-fight winning streak. Diaz lost via unanimous decision. Went the distance with Sylve.
9. Joseph Diaz loses to Alexis Rocha via unanimous decision
On March 14, 2026 Joseph Diaz faced Alexis Rocha in a lightweight bout. Diaz was 33 years old with a record of 34-8-1, and Rocha was 0 with a record of 0-0. Diaz was coming off a loss. Diaz lost via unanimous decision. Went the distance with Rocha.
8. Joseph Diaz loses to Regis Prograis via unanimous decision
On August 2, 2025 Joseph Diaz faced Regis Prograis in a lightweight bout. Diaz was 32 years old with a record of 34-7-1, and Prograis was 36 with a record of 29-3. Diaz was coming off a win, while Prograis was on a 2-fight losing streak. Diaz lost via unanimous decision. Went the distance with Prograis.
7. Joseph Diaz loses to Abraham Montoya via split decision
On November 9, 2024 Joseph Diaz faced Abraham Montoya in a lightweight bout. Diaz was 31 years old with a record of 33-6-1, and Montoya was 0 with a record of 0-0. Diaz was on a 2-fight losing streak. Diaz lost via split decision. Went the distance with Montoya.
6. Joseph Diaz loses to Oscar Duarte Jurado via KO
On April 27, 2024 Joseph Diaz faced Oscar Duarte Jurado in a super lightweight bout. Diaz was 31 years old with a record of 33-5-1, and Jurado was 28 with a record of 26-2-1. Both Diaz and Jurado were coming off a loss. Jurado stopped Diaz via KO in the 9th round. Lasted into the 9th round.
5. Joseph Diaz loses to Jesus Perez via split decision
On February 15, 2024 Joseph Diaz faced Jesus Perez in a lightweight bout. Diaz was 31 years old with a record of 33-4-1, and Perez was 0 with a record of 0-0. Diaz was coming off a win. Diaz lost via split decision. Went the distance with Perez.
4. Joseph Diaz loses to Mercito Gesta via split decision
On March 18, 2023 Joseph Diaz faced Mercito Gesta in a lightweight bout. Diaz was 30 years old with a record of 32-3-1, and Gesta was 35 with a record of 33-3-3. Diaz was on a 2-fight losing streak, while Gesta was coming off a win. Diaz lost via split decision. Went the distance with Gesta.
3. Joseph Diaz loses to William Zepeda via unanimous decision
On October 29, 2022 Joseph Diaz fought William Zepeda for the WBA Continental Americas lightweight title. Diaz was 29 years old with a record of 32-2-1, and Zepeda was 26 with a record of 26-0. Diaz was coming off a loss, while Zepeda was on an undefeated 26-fight winning streak. Diaz lost via unanimous decision. Failed to capture the title. Went the distance with Zepeda.
2. Joseph Diaz loses to Devin Haney via unanimous decision
On December 4, 2021 Joseph Diaz fought Devin Haney for the WBC lightweight title. Diaz was 29 years old with a record of 32-1-1, and Haney was 23 with a record of 26-0. Diaz was coming off a win and Haney was on an undefeated 26-fight winning streak. Diaz lost via unanimous decision. Failed to capture the title. Went the distance with Haney.
1. Joseph Diaz loses to Gary Russell Jr. via unanimous decision
On May 19, 2018 Joseph Diaz fought Gary Russell Jr. for the WBC featherweight title. Diaz was 25 years old with a record of 26-0, and Jr. was 29 with a record of 28-1. Diaz was on an undefeated 26-fight winning streak and Jr. was on a 4-fight winning streak. Diaz lost via unanimous decision. Failed to capture the title. Went the distance with Jr..