Boxing superstar Floyd Mayweather Jr (USA, b.1977) invited hundreds of fans to join an open training session in Moscow, Russia, and they all became record-breakers in the process.
The Largest boxing lessonever saw an outstanding 791 people take part in the lesson, with around 3,000 spectators watching from outside the ring.
Official Guinness World Records adjudicator Sofia Greenacre attended the sporting class to judge the the new record, as well as present Mayweather with a certificate for one of the most incredible records to his name.
Although he recently retired, the world champion boxer earned a whopping $105 million (£70.4 million) between June 2013 and June 2014, making him making him not only the Highest-earning boxer, but also the Highest-earning athlete in any sport.
The boxing legend won all 49 of his fights, including 26 by KO - and he now has another Guinness World Records title to add to his impressive resume of achievements!