Veteran boxing trainer Diego Arrua passed away Friday evening after suffering a heart attack during his wife Sabrina Perez’s interim title fight in Tijuana, Mexico.

The tragic news was learned less than two hours after Arrua collapsed in the corner between rounds nine and ten of Perez’s DAZN-aired interim WBC featherweight title defense versus Australia’s Skye Nicolson. Immediate medical attention was provided as Arrua was rushed to a nearby hospital before he was pronounced dead shortly after 9:30 p.m, local time.

“It is with deep sadness that we have been informed of the sudden death of Argentine coach Diego [Arrua],” WBC president Mauricio Sulaiman revealed on social media Friday evening. "The medical services did everything possible and he died at the QDEP general hospital."

Arrua was 58 years old at the time of his unfortunate passing.

Nicolson (8-0, 0KOs) went on to win the fight via unanimous decision (99-91, 98-92, 97-93) but her team’s immediate thoughts were with the 36-year-old Perez (18-2-1, 2KOs) and her loved ones.

“Victory overshadowed by tragic passing Team Perez coach Diego [Arrua] during the fight,” Paui Ready, Nicolson’s career-long manager, said in an Instagram post. “Our wishes and prayers with them and their family.”

Similar sentiments were offered by DAZN and event promoter Matchroom Boxing.

“RIP Diego,” Matchroom said in a statement posted on its official X (formerly Twitter) account. “Our thoughts and condolences are with Sabrina Perez and your loved ones."

Perez, 36, attempted the first defense of the interim WBC featherweight title she claimed in a ten-round decision over Colombia’s Yolis Marrugo Franco last March 19 in her hometown of Isidro Casanova, Buenos Aires, Argentina.

The former WBO bantamweight titlist fought outside of her home country for the first time as a pro. Urrua and Perez spent the boxer’s entire career giving back to their community.  

Jake Donovan is a senior writer for BoxingScene.com. Twitter: @JakeNDaBox