They always deny it. Perhaps they think it is unsporting to say it aloud. But today was a routine day at the office for the top seeds at the U.S. Open. "It's never routine," Martina Navratilova insisted. "If it ever became routine I would start looking for another job."

The day was full of workmanlike performances. It was a day for honing skills, preparing for the tougher matches ahead, adjusting to the surface that is not only faster than usual but faster than the grass at Wimbledon, according to John McEnroe.

Chris Evert Lloyd, the defending women's champion, dismissed Alycia Moulton, 6-2, 6-2. "It was mainly a match to get used to center court," she said. "Just getting back to the atmosphere--I mean planes flying over every five seconds--getting back into that frame of mind."

Navratilova, the No. 1 women's seed, won her second-round match against Louise Allen, 6-2, 6-0, losing her serve once, just to show she is human.

Ivan Lendl, the No. 2 men's seed, solidified his game and the growing impression that he is on top of it on this surface by dispatching Shlomo Glickstein, 6-1, 6-1, 6-2. Lendl simply overpowered Glickstein with his formidable ground strokes and his attacking game, but he could not drown out the cries of the crowd, "Shlomo, Shlomo." The umpire had to ask for silence.

The No. 1 seed, McEnroe, was almost angelic, beating John Sadri, 6-0, 6-1, 6-4. As the match began, a voice in the crowd cried, "Hey, John, got your sawdust?"

But McEnroe, who threw a handful of sawdust at a fan during his first-round match, didn't hear. He said nothing to anyone. His composure was as complete as his domination of the match. "I want to play Davis Cup," he said. "If I get another fine, I won't be able to go."

McEnroe's fines for the year total $7,300; $200 more would bring a mandatory 21-day suspension.

Early-round outbursts have become the norm for McEnroe at big tournaments. It's as if he has to get something out of his system. Nerves, perhaps. "That might have something to do with it," he said. "You're not into the tournament, not into the flow of it. When people are going around saying you are the favorite or at least one of them, you feel the pressure and you put added pressure on yourself."

McEnroe put pressure only on Sadri today. He allowed Sadri eight points off his serve in the first set, which took all of 23 minutes. McEnroe saved two break points in the first game of the second set and won the next two. There was applause for Sadri when he held in the fourth game.

It took three tie breakers for McEnroe to beat Sadri in the NCAA final five years ago, the first time they met. But their lives and careers have diverged since. "I might have gotten a little better," McEnroe said. "I don't think he will ever play a better match in his life than that. It's as close as you can play and lose. He must have aced me 30 times."

But Sadri's serve is no longer the weapon it was and his game, which hinges on it, has come unhinged. He is ranked 159th and had to qualify for this tournament. McEnroe, whose touch and movement were all there today, had little trouble doing exactly what he wanted.

Yannick Noah, the fourth men's seed, is working his way not only into the tournament but back into tournament toughness after his 42-day suspension. He beat countryman Jerome Vanier, 6-4, 6-4, 6-4, but looked a bit sluggish.

Although he said the tendinitis in his right knee was not a problem, Noah wore a brace on his leg throughout the match and is getting ultrasound treatments. "I'm not very consistent," he said. "I had a lot of break points but I broke him only three times (six actually). I think I have to return serve better."

Asked what percentage of his ability he displayed on the court, Noah smiled and said, "Maybe 92 or 93 percent."

Mats Wilander, the fifth seed, continued to test himself against the alien Deco Turf II surface and continued to progress. He beat Brian Gottfried, 6-3, 6-4, 7-6 (7-3), in a match that was most notable for its eerie third set. Gottfried led, 5-0, but Wilander won the next six games.

Gottfried then broke him as Wilander served his seventh double fault at 15-40. But Gottfried's backhand volley abandoned him in the tie breaker and Wilander went ahead, 5-3, on a lovely backhand topspin lob. "I am glad to be one of the 32 best players on this surface," Wilander said.

For some, like Wimbledon finalist Chris Lewis, there was trial and tribulation. He lost to 16th seed Bill Scanlon, 6-3, 6-3, 6-3. For others, like Aaron Krickstein, 16, it was another new and unexpected day. He beat Scott Lipton, 6-3, 6-1, 6-2.

For still others, it was a day of testing. No. 8 Hana Mandlikova escaped with a 7-5, 7-6 (7-2) victory over Kathy Horvath, the only player to beat Navratilova this year.

Mandlikova is lovely and perplexing. She can make the most graceful shots one moment and the most thoughtless the next. Horvath, who has formidable ground strokes and the concentration Mandlikova lacks, wasted two set points at 5-4 as Mandlikova applied herself for the moment. Mandlikova held for 6-5, then broke again with two of the lovelier shots of the day--a lunging backhand cross-court volley that gave her break point and a sizzling backhand return down the line.

Twice in the second set, Horvath saved match points to force a tie breaker. Mandlikova, who switched to a midsize graphite racket this summer that she says helps her serve and volley, started with a service winner. She took a 3-0 lead and ended it with another service winner and an ace.

"I think I have the potential to be No. 1," she said. "But if I don't do it, it's too tough. If I've never been No. 1, the next day I'm still going to live, anyway."

Vitas Gerulaitis, the 15th men's seed, was another escape artist, losing the first set and losing a 5-2 lead in the third to Fritz Buehning, the man who eliminated him in the first round last year. He won the match, 3-6, 6-1, 7-6 (8-6), 6-2.

For the survivors, it was a day for just getting by. McEnroe may have been speaking for all of them when he said, "We'll find out a little more next match."