Old-timers Martina Navratilova and Jimmy Connors posted straight-set victories and newcomer Jim Grabb recorded the biggest upset so far at Wimbledon today.

Another veteran, fourth-seeded Chris Evert, struggled before winning. Third-seeded Pam Shriver also won, scoring an easy victory despite suffering from mononucleosis.Navratilova, seeking a record ninth Wimbledon singles title and seventh in a row, breezed past American Elly Hakami 6-2, 6-1. Connors, a two-time Wimbledon champion, beat 18-year-old Jason Stoltenberg of Australia 7-6, 6-3, 6-3. Stoltenberg was 2 years old when Connors first played on the grass courts of the All England Club.

Grabb, a collegiate champion at Stanford and playing at Wimbledon for only the second year, upset 11th-seeded Anders Jarryd of Sweden 3-6, 7-6, 6-3, 6-0 in the second round.

"I've had some other wins over big names, but the venue of this one is a little more attractive," said Grabb, ranked 63rd in the world.

Also knocked out of the tournament was 13th-seeded Emilio Sanchez of Spain, a 7-6, 6-3, 3-6, 0-6, 6-1 loser to Petr Korda of Czechoslovakia.

Evert, a three-time Wimbledon champion, beat Christina Singer of West Germany 6-4, 3-6, 6-3. Singer had Evert in trouble with a slicinge backhand and drop shots and drop volleys that died on the low-bouncing court.

Shriver, a semifinalist last year who struggled through a three-set first-round victory, had an easy time in beating Svetlana Parkhomenko of the Soviet Union 6-3, 6-4.

The men's third seed, Stefan Edberg of Sweden, also advanced, with a 6-3, 7-6, 5-7, 6-2 victory over Richey Reneberg of the United States.

In other second-round matches, ninth-seeded Miloslav Mecir of Czechoslovakia beat Alexander Volkov of the Soviet Union 6-2, 6-4, 6-4, and 16th-seeded Slobodon Zivojinovic of Yugoslavia beat American John Ross 6-4, 6-4, 6-4.

As Shriver was finishing her match, the Women's International Tennis Association announced that she was suffering from mononucleosis.