MOSCOW, July 23. /TASS/. Russian boxer Maxim Dadashev died in a US hospital due to injuries, which he sustained in the fight against Puerto Rico’s Subriel Matias last Friday, a source in the boxer’s team told TASS.

"Maxim has passed away. His heart failed," the source said.

Dadashev was hospitalized after his welterweight category fight against Puerto Rican boxer Subriel Matias (under 63.5 kg weight category) on the night of July 20 in Oxon Hill, the US state of Maryland.

The Russian boxer’s team threw in the towel in the 11th round due to Dadashev's rapidly worsening condition, stopping the fight.

After the fight had been aborted, Dadashev started vomiting and then lost consciousness. He was rushed to a local hospital, where doctors diagnosed him with severe brain swelling. A craniotomy surgery followed immediately.

Maxim Dadashev, known by the alias "Mad Max," was 28 years' old. Born in the Russian city of St. Petersburg, he boasted a professional boxing record of 13 wins (11 by KOs) and one defeat, which came last Friday during the fight against Matias, 27, who now sports an unblemished record of 14 wins (all by KOs).

Reached by a TASS correspondent, Dadashev’s Head Coach Buddy McGirt from the United States said he "was heartbroken" after learning the news.

"We feel so sad for him and his family," McGirt told TASS. "I am heartbroken right now."

"He was a great boxer. I wish I had two of fighters like him," Dadashev’s coach continued.

"He was the best. He worked hard and he was a great guy," McGirt added.