World chess champion Anatoly Karpov, 27, followed his loss of Thursday's game by postponing the 12th game of the world title match from Saturday until Tuesday. Karpov said he needed a rest.

Challenger Victor Korchnoi's camp reacted ebulliently to the Karpov slowdown. His aides said he considered it "a good luck omen," and pointed out that his opponents in the three play-off matches had also felt it necessary to seek the first rest days.

In each of these matches - against ex-world champion Tigran Petroslan and Boris Spassky and Soviet Champion Lev Polugaevsky - losses were followed by delays, then by collapses of playing resistance.

As the match continues at the 4,900-foot altitude of Bagulo City, Philippines, the players' age difference (Korchnoi is spotting Karpov 20 years) has not had as much impact as their differences in physical conditioning. Korchnoi runs distance daily. Karpov is thinly built and more sedentary.

In other developments, Korchnoi added Oscar Panno, a grandmaster from Argentina to his list of unofficial "seconds."

Also, as part of the skirmishes in parapsychology, Korchnoi took apparent delight in being seen with Dr. Vladimir Beginer, a Soviet emigre now living in Israel. The doctor has joined Korchnoi's group and sat in the hall unnoticed during the 11th game - while Korchnoi crushed Karpov.

Dr. Beginer functions as Korchnoi's counter to Karpov's parapsychologist, Dr. Vladimir Zukhar from Leningrad. Dr. Zukhar is part of Karpov's official delegation, financed by the Soviet chess federation.

The president of the Soviet federation, ex-cosmonaut Vitaly I. Sevastianov, and Dr. Michael L. Gerahanovich, Karpov's personal physician, had previously taken advantage of Baguio City facilities to undergo psychic "surgery."

The two Soviets sought to have "surgeon" Severino Apeng remove cysts and a wart.After Apeng "prayed, kneaded and mashed," both men's growths remained.

"I feel a bit unhappy that he cannot operate today," the head of a group of Filipino spirtualists said. "It's like that. One day he can, the next day he can't. It's all spiritual."

The rules of the match allow each player three postponements, without requiring reasons, in the first 24 games and one postponement for each 8 games thereafter. There seems to be no limit whatsoever on the players' sources of spiritual advantage. The first man to win 6 games gets $350,000.