Answer
Praggnanandhaa, a 16-year-old Indian chess Grandmaster, defeated World No. 1 Magnus Carlsen in the fifth round of the Airthings Masters Rapid Chess Tournament on February 23, 2022. Praggnanandhaa is the youngest player to defeat Carlsen in classical or rapid chess. The win was a major upset, as Carlsen is considered one of the best chess players of all time.