With the Nazi-Soviet Pact having been concluded on August 23, 1939, Estonia was occupied by the Soviet Union on August 6, 1940. Keres played in his first Soviet Championship at Moscow 1940 (URS-ch12), placing fourth (+9−4=6) in an exceptionally strong field, placing him ahead of the defending champion Mikhail Botvinnik, among others. The Soviet Chess Federation organized the "Absolute Championship of the USSR" in 1941, with the top six finishers from the 1940 championship meeting each other four times; it was split between Leningrad and Moscow. Botvinnik won the event, one of the strongest ever organized, with 13½/20, and Keres placed second with 11, ahead of Vasily Smyslov, Isaac Boleslavsky, Andor Lilienthal, and Igor Bondarevsky.