Geller began to make his mark in the late 1940s, as he won the USSR Championship semifinal qualifier at Tbilisi 1949 with 11½/16, thus advancing to the final later that year. His finals debut was sensational at URS-ch17 at Moscow; as a virtual unknown he tied for 3rd–4th places with 12½/19, behind only winners David Bronstein and Vasily Smyslov. Geller defeated such established players as Semyon Furman, Isaac Boleslavsky, Alexander Kotov, Salo Flohr, fellow finals debutant Tigran Petrosian, Viacheslav Ragozin, and Grigory Levenfish. Despite this showing, he was obliged to return to the semifinal level the next year, but advanced with a third-place finish in the 1950 qualifier at Kiev with 9/15. At URS-ch18 at Moscow 1950, Geller made 9/17 for a shared 7th–10th place; the winner was Paul Keres. Also in 1950, Geller won the Ukrainian SSR Championship in Kiev, the first of his four titles in that event; he repeated from 1957 to 1959, with all three events in Kiev. Geller in 1950 made his international debut at the Przepiorka Memorial at Iwonicz Zdroj with 11½/19 for seventh place in a powerful field; Keres won again.