The sun finally came out at Wimbledon today, and so did the people, Nearly 35,000 spectators jammed the scenic, flower and shrub-lined grounds of the All England Tennis and Crocquet Club on a day that produced no earthshaking results but plenty of the colorful footnotes that make the world's premier tennis tournament so fascinating.

Not many of the favorites in the men's and women's singles played today. Most of them had managed to slip through the rain drops and complete their first-round matches on the first two days of the championship, when persistent showers washed out all but 40 matches.

The highest of the men's seeds to see action today was No. 8 Victor Pecci, the 6-foot-4-inch Paraguyan who has had a lean year after sparkling last spring as brightly as the diamond he wears on his right ear. He whipped Californian Matt Mitchell, the 1977 NCAA champion, 7-5, 6-1, 7-6.

The leading lady of the day was No. 4 seed Evonne Goolagong Cawley, the champion of 1971 who yearns for one more Wimbledon title before settling down to have her second child and retiring from competitive play. She easily disposed of Sharon Walsh, 6-1, 6-2, and then hurried off to relieve the babysitter looking after her 3-year old daughter.

The only seeded player to lose -- the first in a tournament that has been uncharacteristically slow in generating any real on-court excitement -- was No. 14 Victor Amaya, the 6-foot-7, 225 pound left-hander from Holland, Mich., who nearly beat Bjorn Borg in the first round two years ago.

Now ranked No. 20 in the world Amaya was beaten by 6-foot-4-inch Hank Pfister, ranked No. 38, in a very minor upset. This was a battle of concussive serve-and-volley. Had there been a seismograph measuring the impact of the Center Court, it might have registered alarming numbers on the Richter scale. Pfister was a shade sharper and more, consistant in returning serve and won, 3-6, 6-4, 3-6, 6-3.

Earlier on the Centre Court, No. 16 Jose-Luis Clerc avoided the notoriety of becoming the first seed to fall when he completed a 1-6, 3-6, 7-5, 7-5, 6-4 triumph over Vijay Amritraj, the elegant Indian who always seems to go down to memorable defeats at Wimbledon. (Last year, he came closer to beating Borg here than anyone else has since 1975.)

This was the resumption of a match that had been suspended by darkness Tuesday night on neighboring Court No. 1. After losing the first two sets in a hurry, Clerc -- the clay-court specialist whose victory over John McEnroe spurred Argentina to its Davis Cup upset of the United States this year -- decided to abandon his customary backcourt style in favor of a net-rushing game better suited to fast, skiddy grass.

Returning serve ferociously and volleying better than he thought he could, Clerc won the next two sets to even the match, then spent a sleepless night before finishing the job.

"I think this is normal, no"? said the improving 21-year old. "This is such a big tournament, and I don't like to lose in the first round of any major tournament. I was awake all night, just thinking returning Amritraj's first serve."

All of the men's singles first round, and most of the women's, were finished today. The 18 grass courts bustled with activity from early afternoon to nightfall. The rest of the backlog caused by the rain should be eliminated in the next two days, since the start of play has been moved up to noon from the traditional "2 p.m., precisely."

The favorites will be back in action Thursday, but today was for unlikely heroes and heroines, like Adriano Panata, the dashing Italian, who upended Californian Erik van Dillen, 3-6, 2-6, 7-6, 7-5, 9-7, much to the delight of a raucous group of Italians that turned Court No. 13 into a reasonable facimile of the Latin Quarter, and Andrea Jeager, the youngest player ever seeded at Wimbledon (No. 14), who won her debut over Anthea Cooper, 6-3, 6-3.