Challenger Gary Kasparov scored a stunning victory yesterday in Game 16 of the world chess championship match in Moscow -- a victory that left more than 1,000 fans in the Tchaikovsky Concert Hall stamping their feet and shouting "Gary, Gary" minutes after the players had left the stage.

It was the most exciting game so far in this match, with Kasparov showing a full return to his distinctive, brilliant tactical style. The game began as a replay of Game 12, which had featured an innovative treatment of the ancient, deeply analyzed Sicilian defense. In that game, the shortest in the match, champion Anatoly Karpov managed to neutralize Kasparov's attack, and a draw was negotiated after only 18 moves. By replaying the first 10 moves and introducing what looked like an improvement on move 11, Karpov in effect challenged Kasparov to come up with something new.

He did. In moves 13 to 20, after sacrificing a pawn for tactical advantages, Kasparov rapidly reduced his opponent's mobility. By move 27 Karpov was in a state of almost total paralysis. He finally traded his queen for two knights and a bishop, but Kasparov's few remaining pieces were ready to force a victory. In the final position, a checkmate was inevitable. If Karpov had played it out rather than resigning (41 Nf1, Rxf1ch; 42 Bxf1, Qxf1, mate), Kasparov would have been left with only his queen and a few pawns on the board -- but the queen in the precise winning position.

The victory puts Kasparov in the lead with a score of 8 1/2 to 7 1/2, and it places considerable pressure on the champion. With only eight games remaining, Kasparov needs only to play for a draw, and he has held Karpov to a draw 51 times in the last 13 months, including 14 consecutive draws last December and January.

If the match is a draw, Karpov keeps the championship title. He can do this by winning one game and drawing the rest, but he needs at least two victories to win the match and to justify any claims that he is a better player. In the past, he has talked of giving Kasparov "chess lessons" by playing against him. He is unlikely to repeat such a boast. He is also unlikely to use this variation of the Sicilian defense again soon.