Simplify the following text for a Grade 10 native English-speaking person.
Original: In July 2008 in Berlin , a 19-year old Russian mathematics student Nikolai Sazhin won the `` World Champion '' title in chess boxing by defeating Frank Stoldt .
Simplified: In July 2008 in Berlin , a 19-year old Russian mathematics student Nikolai Sazhin won the title of `` World Champion '' in chess boxing by beating Frank Stoldt .