In March 1940, he took 4th in Lviv (Western Ukrainian championship, Abram Khavin won). In 1940, he tied for 16-17th in Kiev (the 12th Ukrainian Chess Championship, Isaac Boleslavsky won). In August 1940, he won in Lviv, followed by Appel, Friedman and Schächter.
In September–October 1940, Gerstenfeld took 17th in Moscow (the 12th USSR Chess Championship). The event was won by Andor Lilienthal and Igor Bondarevsky. In January/February 1941, he won ahead of Appel, Friedman, Emanuel Rubinstein and Schächter, in the Lviv City championships.