Victor Korchnoi got into time trouble, threw away a possible winning chance and had to settle for a draw in the first game of his chess match with Boris Spassky in Belgrade, Yugoslavia.

The two Russian grandmasters adjourned the game - first in a 20-game series - on Monday, with Spassky sealing a move that offered a temporary sacrifice. Korchnoi, playing white, offered the draw before the 53d move, after the game was resumed yesterday. Spassky will have white today in the second game.

The first player to score 10 1/2 points in the match will win the right to challenge Anatoly Karpov for the world championship next year. Spassky, who has been living outside of the Soviet Union for over a year, had a small Soviet flag on his side of the playing table, and he has two strong seconds supplied by the Soviet Chess Federation - a sign that the Russians are eager for him to beat Korchnoi.

One of the seconds is Igor Bondarevsky, his old trainer, who accompanied him to Reykjavik when he lost his championship to Bobby Fischer in 1972. The other is Efm Geller, one of the world's strongest grandmasters.

Their presence is a sharp contrast to Spassky's semifinal match against Hungarian grandmaster Lajos Portisch, when the Soviet Federation offered him seconds so weak that he refused to accept them and played without help.

Korchnoi, who defeated from the Soviet Union in July 1976, is seconded by Raymond Keene, a young British grandmaster noted for his expertise in unorthodox openings.