Slobodan Zivojinovic of Yugoslavia upset John McEnroe, 2-6, 6-3, 1-6, 6-4, 6-0, today in the quarterfinals of the $1.5 million Australian Open tennis championships.

Zivojinovic, 22, is ranked 66th in the world and was unseeded. The defeat means that second-seeded McEnroe, 26, ranked No. 2 in the world, has failed to win a Grand Slam title this year.

McEnroe's serve and delicate touch held no mysteries for Zivojinovic, who blasted his way to victory. He served immaculately in the final two sets and defused McEnroe's serve with some blockbusting returns.

In the women's singles, Chris Evert Lloyd and Martina Navratilova advanced to the semifinals with straight-set victories.

Top-seeded Ivan Lendl of Czechoslovakia moved into the men's quarterfinals today with a 6-3, 6-2, 6-7, 6-2 win over unseeded South African Christo Steyn.

Lendl was given a code of conduct violation for ball abuse in the third set and bounced his racket angrily on several occasions.

He began impressively, hammering four aces in his first service game. But Steyn, a 24-year-old graduate of the University of Miami ranked 170th in the world, often kept Lendl off balance and rallied in the third set.

Steyn led at 5-2, had a set point at 5-3 and, after Lendl had fought back, took the tie breaker 7-3.

The fourth set was all Lendl's, however.

Evert beat Bulgarian Manuela Maleeva, 6-3, 6-3, in a Tuesday match and will play her semifinal against fifth-seeded Claudia Kohde-Kilsch of West Germany. Kohde-Kilsch had a 6-4, 6-0 victory over 10th-seeded Catarina Lindqvist of Sweden.

Evert had watched her husband, John Lloyd, cause the upset of the day in the men's singles, beating seventh-seeded Swede Joakim Nystrom, 6-2, 1-6, 6-4, 6-7 (4-7), 6-4.

Fifth-seeded Stefan Edberg of Sweden had to save two match points in the third set before defeating Australian Wally Masur, 6-7, 2-6, 7-6, 6-4, 6-2.

Navratilova's victory over Czechoslovakian Helena Sukova included a measure of revenge. It was Sukova who defeated Navratilova in the semifinals here last year, ending her bid to complete a historic calendar year Grand Slam. This time, Navratilova raced through, 6-2, 6-2, in a 58-minute blitz.

"It wasn't a personal vendetta -- just a professional one," said the Czech-born Navratilova, who next plays Hana Mandlikova. Mandlikova trounced Zina Garrison of Houston, 2-6, 6-3, 6-3.