At age 15, Azerbaijani grandmaster Teimour Radjabov defeated reigning world number one Garry Kasparov at the 2003 Linares tournament, becoming the youngest player in history to beat a reigning world No. 1 in a tournament-time-control game.
Record no. MRB-2026-006406
Youngest Player to Defeat a Reigning World No. 1
Reference Record – Not Certified
This record is compiled from publicly available sources for reference. It has not been examined or certified by The Book of World Records.