Former junior lightweight titleholder Joseph Diaz Jnr has had some great memories challenging the best in the world.

Diaz Jnr, who held the IBF 130lbs title for a little over a year in 2020-2021, ended a three-fight losing streak earlier this month after winning a unanimous decision over eight rounds with Jorge Luis Valencia Diaz in Tijuana, Mexico.

BoxingScene: What was the toughest fight you had as a professional?

Joseph Diaz Jnr: Probably William Zepeda. He threw a lot of punches, and at that time [in 2022] I was still partying and drinking, so that fight was a lot more difficult. It was a harder fight than I expected, because of my preparation. He was a tough fight because of the volume he brought in that fight. 

BS: Who’s the best you’ve sparred?

Diaz: Shakur Stevenson. I sparred with him back in 2017, 2018, and he was a very slick, crafty fighter. His distance control combined with him making you not want to throw punches [is what makes him the best] because when you throw a punch, he is attacking and dictating the pace. He is hard to figure out because of his stance and how long he is. He is an awkward, good fighter. 

BS: Who had the fastest hands? 

Diaz: Gary Russell Jnr. His hand speed was incredible. I thought I had that fight, too. I look back on that fight [in 2018], and I look back at the Devin Haney fight [in 2021]. If I had been just a little more aggressive and opened up a little more, I could have had both of those fights. I don’t regret anything. Everything happens for a reason, and I am the person I am today because of those fights and everything that happened in my life. I am grateful for everything that happened in my life, all the ups and downs. 

BS: Who is the biggest puncher you faced?

Diaz: Oscar Duarte [in 2024]. Every time he punched, it was like electricity; like electric punches. He was a big fighter and a strong fighter. 

BS: Who was the greatest fighter you saw who didn’t have the success you expected?

Diaz: Frankie Gomez. He could have been a world champion. He is a really good fighter, but he just let the demons and temptations get the best of him. I hope that he is okay and doing good now. I wish him all the best.

Lucas Ketelle is the author of “Inside the Ropes of Boxing,” a guide for young fighters, a writer for BoxingScene and a member of the Boxing Writers Association of America. Find him on X at @BigDogLukie.