Promoter Eddie Hearn has confirmed that Joshua has activated a rematch clause in his contract with Andy Ruiz Jr for a rematch later this year.
Joshua suffered a shock defeat to the Mexican in New York this past weekend, but will have a chance at reclaiming his WBA, IBF, and WBO heavyweight champion titles in November/ December this year.
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The 29-year-old Birt was the huge favourite heading into the bout at Madison Square Garden, but lost via a seventh-round TKO.
"After meetings with AJ, (trainer) Rob (McCracken) and the management team in NY, we have today triggered the contracted rematch clause with Andy Ruiz Jnr," Hearn tweeted. "The fight will take place in Nov/Dec at a venue to be confirmed shortly."