Gary Kas-parov threw a surprise move in his Ruy Lopez strategy Wednesday and went on to defeat challenger Anatoly Karpov in Game 2 of the 24-game World Chess Championship.

Kasparov's maneuvering began to take shape at move 19 and culminated at move 25, when he sacrificed two pieces for a rook and a pawn and took control of the center, said Al Chow, a spokesman for the championship games.Kasparov broke into a smile following the defeat of his bitter rival, Chow said. The first game between the two chess masters on Monday ended in a draw. Kasparaov leads the tournament 11/2-1/2.

The match for the winner's share of a record $3 million purse was played at the venerable Hudson Theater, in the Hotel Macklowe on West 44th Street just off Times Square.

"It was very exciting - a lot different from the last one. This was not a quiet game," said Chow. "Kas-parov attacked Karpov very decisively. It was a psychological defeat (for Karpov)."

"Karpov played his first 17 moves fast. He was totally secure, maybe overly secure," Chow said. "But Kas-parov invented something new. This was all homework."

Kasparov, an aggressive player known for his willingness to sacrifice pieces for position and his penchant for disconcerting moves, began the game with the Zaitsev variation of the Ruy Lopez.

Karpov is generally a strong defensive player, "but Kasparov played a new move on move 19," Chow said. "This plan allowed white to build up a very strong center. He proved that it was good when he made move No. 25.

"Kasparov sacrificed two pieces for a rook and a pawn at move 25, and it led to a very strong attack," Chow said.

Kasparov is the world's greatest recognized authority on the black of the Ruy Lopez, Chow said.

After the first 18 moves, Karpov began "consuming a lot of time," Chow said. Each players has 21/2 hours to make 40 moves.

Some chess masters speculate that Karpov might postpone Friday's game and ask that the rivals meet on Monday instead, giving him time to rethink his game.

The Soviet masters will play at the Hudson on Mondays, Wednesdays and Fridays for five weeks or until they complete 12 games. The tournament then moves on to Lyons, France, for the second half of the tournament.

The contest is the first World Chess Championship held in New York since 1907. Tickets at the Broadway theater are $100, $50 and $25.