Badou Jack (right) stepped up from super-middleweight for the first time to face Nathan Cleverly

Nathan Cleverly retired from boxing after losing his WBA light-heavyweight title to Badou Jack in Las Vegas.

The 30-year-old Welshman was stopped in the fifth round by his Swedish opponent on the undercard of Floyd Mayweather’s victory over Conor McGregor.

It was a fourth career defeat in 34 fights for Cleverly, who had won the WBA title with victory over Juergen Braehmer in October 2016.

“Time to say goodbye. Thank you and goodbye boxing,” he wrote on Twitter.