SEVILLE, Spain (AP) _ A blunder by title-holder Garri Kasparov allowed challenger Anatoly Karpov to score a dramatic victory in the second game of their World Chess Championship match.

The win on Wednesday gave Karpov, who was playing black, 1 1/2 points, to Kasparov's 1/2 point.

During the latter stage of the game, a black cat was seen prowling beneath the stage where Kasparov and Karpov sat.

Kasparov's lapse occurred as both players were running low on time while involved in a complicated middle-game position.

In an inferior position, Kasparov made his 26th move, but failed to press his time clock. For nearly three minutes the world champion stared at the board while his precious remaining time ran down.

After he realized he had less than a minute left for the final 14 moves, Kasparov glared at Karpov, who had been analyzing the position quietly.

Kasparov shook his head twice after hitting the button to stop his own clock from running, and to start Karpov's clock.

Each player is given 2 1/2 hours for his first 40 moves in a game. For the following 16 moves, each is allowed one hour.

After committing the blunder, Kasparov struggled to defend his position but could not prevent Karpov from closing in for the kill.

Faced with an unstoppable mating attack with queen and knight, Kasparov resigned after Karpov's 32nd move.

''The match has just started, but this shows that Kasparov's nerves are not as they should be for him to retain his title,'' said American Grandmaster Maxim Dlugy. ''I've never seen a player forget to press his clock in a mutual time-scramble.''

When play began, Kasparov a surprise by playing the English opening for the first time in a championship contest.

Karpov wheeled out a surprise pawn thrust at move No. 9 that sent Kasparov into an 80-minute marathon search for the best answer.

Kasparov chose an approach that left both Soviet grandmasters in a muddle, unable to predict the course of the zigzag encounter.

Former World Champion Boris Spassky had predicted, ''Today we're going to see a bloodbath, just like a bullfight. The bull will be Kasparov and the bullfighter Karpov.''

At move No. 17, Kasparov sacrificed a pawn to shatter black's kingside defenses, but this allowed the challenger to penetrate in the center of the board.

Kasparov finally captured the pawn that had been thrust into his position at move No. 9, but Karpov's pieces began to hover around the white king.

Chief Arbiter Gert Gijssen of the Netherlands told reporters he was not allowed to inform Kasparov that he had left his clock running. Karpov would have been allowed to, he said.

Gijssen also said a cat had been running around under the stage, creating noise during the latter part of the game.

Coming as it does with the disadvantageous black pieces, Karpov's victory is likely to add to Kasparov's psychological shock.

The winner of the 24-game match is the first player to score 12 points. A win scores a point and a draw a half. In the event of a 12-12 tie, Kasparov will retain his title.

The third game is scheduled for Friday with Karpov playing white.