As had been widely expected, challenger Anatoly Karpov resigned Game 4 of the world chess championship match without returning for a second day of play at the Teatro Lope de Vega in Seville, Spain. The resignation puts champion Gary Kasparov even with the challenger at one victory and two draws each.

This actually gives the 24-year-old champion a small but significant advantage, since he retains his title if the match ends in a tie. Otherwise, the 24-game match will be won by whoever wins six games or amasses 12 1/2 points (draws count half a point).

Kasparov's 41st move, kept in a sealed envelope until Karpov's resignation, would have been Rd8. Analysts said that move could have led to a forced checkmate within 12 moves.

Game 5 is scheduled to begin today with Karpov, 36, playing white. In the two previous games of this match, he has opened with his queen's pawn and Kasparov has responded with the Gru nfeld Indian Defense, leading to rather uneventful games.

Both of the games in which Kasparov had white have used the tricky English Opening. The first, in which Karpov unveiled a striking new move, was won by the challenger after the champion got into serious time trouble.

For Game 4, Kasparov returned to the English Opening and Karpov declined to use his new move, doubtlessly anticipating that Kasparov and his team had found an answer. In spite of his trouble with time in Game 2, Kasparov opened Game 4 by letting his clock run for three minutes while awaiting Karpov's arrival -- late as usual.