This mighty clash between the top two Soviet Grandmasters was Botvinnik's first title defence after becoming World Champion in 1948. Amazingly, the man who had dominated Soviet and World chess was only able to defend his title by the skin of his teeth after a most ferocious and determined onslaught from his youthful challenger David Bronstein. The controversial 23rd game where a demoralised Bronstein may have resigned prematurely was the key to Botvinnik's ultimate success.