Former world chess champion Boris Spassky fell behind in his current drive to regain his title, losing the eight game of his match with Hungarian grandmaster Lajos Poortisch. The score of the 16-game match, being played in Geneva, now stands at 4 1/2 to 3 1/2 in favor of Portisch.

Across Lake Geneva, in the French resort town of Evian-les-Bains. Soviet grandmaster Lev Polugaevsky finally won a game from his former compatroit, Vitor Korchnoi. Korchnoi, who defected from the Soviet Union a year ago, still leads comfortably by 5 to 2. He needs a total of 8 1/2 points (one point for a win, half a point for a draw) to win the match.

Meanwhile, in Lucerne, at the opening session of an extraordinary meeting of the International Chess Federation (FIDE), the Soviet Union introduced a resolution to expel South Africa had been expelled at the regular FIDE Congress in Nice in 1974, but was reinstated at the 1976 FIDE Congress (held in Israel and boycotted by most Communist and third-world countries) after evidence was offered that chess activities in South Africa are not segregated.

West Germany countered the Russian proposal in Lucerne with an argument that the meeting was invalid because less than one-third of the member nations in FIDE were represented.