He was invited to play in the first international chess tournament, the London 1851 tournament, where he scored ½–2½ and was defeated in the first round by the eventual winner Adolf Anderssen. One of the games was finished in a mere 20 minutes after a horrific blunder Staunton described as having been "never equalled even among beginners of the game". The other loss was equally one-sided. During his time in London, however, Kieseritzky also played an offhand game against Anderssen which has so thrilled generations of chess players that it has been dubbed "The Immortal Game". Despite losing, it was in fact Kieseritzky who recorded and published the game during his period as editor of "La Regence".