When they led Gene Mayer off the court toward the press conference today, he wasn't sure which way to go. It had been a long time between big victories at the U.S. Open. "It was never like this before," he said, squinting into the television lights. "My old eyes aren't adjusting."

Soon, he was in full rhetorical flight, explaining his 6-4, 6-2, 6-3 upset of sixth-seeded Jimmy Arias. Mayer, who was ranked fourth in the world only four years ago, has dropped to 20th amid a plethora of wrist and thigh injuries. He is unseeded this year for the first time since 1979. As he spoke about how hard it is to sustain the promise of youth, an authoritative voice interrupted -- "Thank you, Gene" -- signaling the end of the monologue.

The voice belonged to Arias, who has had a long, hot summer. He knows how hard it is to remain a phenom. In 1980, at age 16, he became the youngest male to compete in the Open. Last year, he was a semifinalist. This year, he said, "I didn't mentally feel 100 percent. I wasn't as psyched up as I should have been."

Kathy Jordan, the fifth women's seed, learned the same bitter lesson in losing to unseeded Helena Sukova, 6-3, 6-3. Jordan, a Wimbledon semifinalist, has worked all year to raise her ranking from 14th to fifth. "After working so hard, and not to do well, you begin to ask yourself, what's the use?" she said. "Everybody wants to quit after losing. But you just have to take a couple of hours or days and get it back together."

Stefan Edberg, the young Swedish phenom, will need some time to recover from his match with top-seed John McEnroe. It was a debacle. McEnroe dissected him, 6-2, 6-0, 6-1, in 75 minutes. Edberg, who won the junior grand slam last year, got six points off McEnroe's serve. He double-faulted the first time he served and was broken for the first time on his third double fault of the game. The first set ended when he double-faulted again.

His panic was perceptible, McEnroe's mastery complete. "I'm sure he put undue pressure on himself," McEnroe said. "There was no real reason for people to expect him to have a real close match with me. I'm having my best year to date and he's 19 (next January) years old."

McEnroe says Edberg has the potential to be a great player. But tonight he looked like the man Martina Navratilova could beat.

The day was equally traumatic for Juan Aguilera, the 11th seed, who lost to Robert Green, and equally uneventful for Jimmy Connors, the defending men's champion, and Pam Shriver, the fourth women's seed, who advanced in easy straight-set victories.

Jordan beat Shriver in the quarterfinals of Wimbledon. In the best of times, she looks wired, rocking back and forth at the base line while waiting to return serve. Today, she looked overanxious. Her return abandoned her.

"Kathy is getting upset in every match after the first point," said Sukova. "Some keep it inside. She doesn't."

Sukova, who is ranked 18th, resembles Shriver: tall and gangly and graceful in her way. Sukova's mother Vera was a Wimbledon finalist three years before her daughter was born in 1965.

This year, Helena Sukova was expected to come into her own. But she has struggled, beset by self-doubt. When she lost to Jordan six months ago, 6-3, 6-0, it was one more disappointment in a disappointing year. "She just smashed me off the court," Sukova said. Not today. "She was ready," Jordan said. "I was lethargic."

Serving and volleying, Sukova won the first set and was up by 5-1 in the second, before Jordan won two straight games for the first time in the match. Sukova served for the match at 5-3. Five times, Jordan fought off match points. Once, she had a break point and wasted it with another errant return. On the sixth match point, Sukova volleyed into the open court and raised her fists in glee. Jordan went and sat under the stands, comforted by her mother.

Sukova next will play Gabriella Sabatini of Argentina. Sabatini, 14, became the youngest player to reach the third round by defeating Kim Shaefer of Alexandria, Va., 6-4, 6-1. The match was effectively over when Shaefer double-faulted on set point in the first set. Sabatini won the French and Italian junior championships this year. She has the skills to become the next great player in the women's game. The future beckons.

Arias knows what it is to be young and unaffected by pressure. Last spring, he won three titles in Italy, and then the U.S. Clay Court Championship in the summer. This summer has been more cruel. He lost to Aaron Krickstein in the quarterfinals of the U.S. Pro Championships and then to Dan Goldie in the second round in Washington.

He struggled to beat Terry Moor in the first round and struggled from the outset today. Although he and Mayer have practiced together frequently, they had never played each other. Mayer's imaginative and unorthodox style -- his two-fisted forehand and backhand, his deft touch -- gave Arias pause. Mayer kept him off-balance, changing the pace, and never let Arias find his rhythm. He wanted to keep the points short and he did, taking the net and taking charge.

He broke in the ninth game of the first set when Arias mis-hit a backhand wide, one of 11 backhand unforced errors. Arias also made 14 unforced forehand errors: 14 too many.

"What surprised me was that my forehand kept going over the fence," Arias said. "Because he hits so many different shots, it was hard to get my rhythm, especially on center court. The wind swirls around; the crowd walks around. I never felt in control of my shots, much less the match."

Perhaps, Arias said, if he had won the first set -- at 4-3, it was 15-40 on Mayer's serve and Arias couldn't convert -- it would have been different. Mayer, who holds the record for having retired from 16 matches in his career, does not like drawn-out affairs.

But this time, it was Arias who was hurting. He was limping on the way to the dressing room, a result of pulling ligaments in his right foot during his first-round match. He said it didn't affect his play.

Billie Jean King has retired from singles competition but she is making her presence felt, playing doubles with Chris Evert Lloyd, and they are seeded ninth. "Three weeks ago, Chris asked me," she said. "I thought she was talking to somebody else. I said, 'That was your first mistake ever, Lloyd.' It'll be hit and giggle with me. Until I miss the first shot."

They won their first-round match over Claudia Monteiro and Yvonne Vermaak, 3-6, 6-1, 6-0.