Reshevsky lost his first match in 1964 but it was a four-game play-off match following the Amsterdam 1964 Interzonal, where he had tied for 8th–9th with the Hungarian Champion Lajos Portisch. The final spot for advancement to the Candidates Match was at stake and there was little time between the end of the Interzonal and the start of the match. Reshevsky's earlier matches had always had a lead time of several months, which allowed him to prepare his openings, but he proved to be at a distinct disadvantage in this area against Portisch, who was a full-time chess professional and always excellent in his opening preparation. Reshevsky was quickly outplayed on the White side of the Queen's Gambit Accepted in the first game and eventually fell on time in a lost position. In the second game, he played sharply with Black but Portisch was able to exchange the queens and a pair of rooks, thus draining much of the tension in the position. A draw by threefold repetition of position soon ensued. In his last game with White, Reshevsky had to go for broke. An Open Sicilian arose but Portisch seized the initiative on the queenside; having gained a clear advantage, he was able to translate it into a crushing kingside attack, thus winning the match and the final Candidates spot. Amsterdam 1964 was the first meeting between these two chess greats and Portisch was to prove a difficult opponent for Reshevsky, whose lifetime score against him was (+0−4=9).