He won the 2nd World Junior Chess Championship in 1953, ahead of such future strong Grandmasters as Borislav Ivkov, Bent Larsen, and Fridrik Olafsson.

This result was probably the peak of his career, as it advanced him to the 1956 Candidates tournament in Amsterdam, the winner of which would play a 24-game match for the World Championship with Mikhail Botvinnik.

Chessmetrics.com, which attempts to rank players from before the introduction of FIDE ratings, estimates that he was as high as 18th in the world in his prime, in late 1955.

He twice in a row won the strong Palma de Mallorca international invitational tournament: 1971 together with Ljubomir Ljubojević, 1972 at the best tie-break along with Viktor Korchnoi and Jan Smejkal.

He was still active as of 2008, finishing third in the Bobby Fischer Memorial tournament held in Villa Martelli.