Pan American games records were broken in four of the five swimming events tonight, with emotional victories by Brazil's Ricardo Prado and Canada's Kathy Bald ending U.S. domination for a night, at least.

It was that fifth event that may have meant the most in the long run, however, as Sippy Woodhead returned to the victory stand after a long absence by winning the 200-meter freestyle.

Woodhead owns the world record for the event and in the 1979 Pan Am Games she won five gold medals. But tonight's victory was her first in a major long-course race since the dual meet against the Soviets in 1981.

Woodhead, 19, attended the University of Texas, then Southern California; she lost her coach and her confidence, and at one time seriously considered quitting the sport. But tonight, as she spoke between congratulatory hugs from happy teammates, she seemed to possess her old confidence.

"I wanted to keep my mind clear, use proper strategy and pay attention to what was going on," Woodhead said. "I was real relaxed for the first time in three years. I was confident and I swam my own race.

"Even a week ago, when I was up on the blocks, I was scared to death. My heart would beat 300 times a minute. It's been a few years since I swam like this and I'm excited about it."

Woodhead, third at the 100-meter mark, turned it on in the last 50 meters to beat Mary Wayte, the U.S. champion, and Canada's Julie Deigneault.

With its shooters winning four more gold medals, the United States finished the fourth day of competition with 39 gold medals and 77 overall. Runner-up Cuba had 29 golds and 63 overall; Canada had six golds and 40 total medals.

The only question about Prado's runaway victory in the 400-meter individual medley was whether he could break his own world record. He missed by almost two seconds with a time of 4:21.43.

The crowd chanted, "Bra-zil," when Prado reached the starting area and repeated it as Prado walked around the pool following his victory.

"I knew how much everyone wanted me to win, but I tried not to think about it," said Prado, a student at Southern Methodist. "I came here with one thing in mind, then with all the confusion here I couldn't get motivated.

"But last night my delegation put me up in a hotel and, even though they were saying, 'We're doing this for you, you'd better win,' I felt a lot better today."

Bald won the 200-meter breaststroke in 2:35.53, edging Susan Rapp, formerly of Alexandria, Va. After Bald won, she was hugged by teammate Anne Ottenbrite, the Commonwealth Games champion who was disqualified in the morning preliminaries for using an illegal kick.

Ottenbrite has a disjointed knee, which makes the required breaststroke kick difficult. She has been disqualified three times this year after having been permitted to use her unusual kick in the world championships.

"Before I swam, I told her, 'This one's for you,' " Bald said. "I was basically thinking of Anne while I swam. It made me cause more to try to win. The gold is nice to have, but I feel Anne deserved it."

Rapp, who attended Edison High School before her father, an Army engineer, was transferred to Minnesota 14 months ago, agreed Ottenbrite was the best in the field.

"She had 2:33 this morning, so she probably would have won," Rapp said. "This is my first big meet like this, although I was on the 1980 Olympic team, and I'm pleased to finish second. I wish my time (2:37.91) had been a little bit faster, though."

Matt Gribble, a University of Miami senior, got the United States off to a fast start by winning the 100-meter butterfly in 54.25 seconds, with teammate Pablo Morales second.

A downpour stopped while the swimmers were on the blocks and a subsequent false start did not help their composure, so Gribble was philosophical about his inability to lower his own world record of 53.44.

"We were all a little cold and a little tight when we got out of the water after the false start," Gribble said. "That made it tough. When I'm cold on the blocks, I usually stiffen up in the last 50 and it definitely had an effect on me."

The third U.S. gold of the night in swimming came in the 4x200-meter freestyle relay, with David Larson, Rich Saeger, Bruce Hayes and Rowdy Gaines clocking 7:23.63 to cut 7 1/2 seconds off the Pan Am record.

In diving today, Greg Louganis won the gold medal and fellow American David Burgering took the bronze in the men's three-meter springboard competition.

Louganis, who received perfect 10 scores on three dives, never trailed in the event and totaled 724.02 points. Abel Ramirez of Cuba won the silver over Burgering, of Mission Viejo, Calif. Ramirez totaled 631.26 points and Burgering 616.35.