World chess champion Anatoly Karpov has won his second game in a row and taken a substantial lead in his match with challenger Gary Kasparov. The game, played Saturday in Moscow's Tchaikovsky Concert Hall, was adjourned after white's (Kasparov's) 41st move. Kasparov resigned yesterday by telephone, giving the champion a 3-2 lead. The match goes to the first player who wins six games, or the one who is leading when a 24-game limit is reached.

Although Karpov is only one point ahead, Kasparov must win at least two more games to take the championship. Karpov retains the title in case of a tie.

With three decisive games (as opposed to draws) in the first five, this match is proving considerably more active than the previous Karpov-Kasparov series, which was abruptly ended on Feb. 9. That match had only eight won games out of 48 played.

To have any hope of winning, the challenger will now have to push for decisive games, while Karpov can relax and play for draws. The champion has always seemed most at home in this kind of situation. But in the early stages of this match, after losing the first game, he has demonstrated his ability to come from behind.

Karpov's two successive wins are a serious psychological blow to the challenger. Kasparov won the first game of the match and nearly won the second; he had played 24 games in a row without losing to Karpov before suffering two quick defeats on Friday and Saturday.

Karpov sealed his 41st move Saturday with an advantage of one pawn -- a well-protected passed pawn. Opinion was unanimous among grandmasters on the scene that the champion had a winning advantage. There was no prospect of an immediate victory, but Karpov had a completely secure position and seemed able to force an eventual win, probably after making Kasparov sacrifice a piece to stop the passed pawn. Karpov's sealed move, No. 41 . . . Nd3, was a strong one, attacking both the queen and the f-pawn and allowing Karpov to force an exchange of queens if he chose.

Kasparov opened the game aggressively with a Ruy Lopez, one of the oldest and most analyzed openings in chess. His early moves quickly put his bishops in active positions directly attacking Karpov's castle. But this was done at the expense of pawn dislocations and ultimately the loss of a decisive pawn on the queenside, while Karpov tightened his defense. The play was typical of both players: Kasparov vigorous but impetuous; Karpov slow, disciplined and careful, willing to take a small, risk-free advantage and nurse it to a winning position.

The next game is to be played tomorrow. The expectation in Moscow is that Kasparov will ask for a postponement to give him time to recover from his setback.