For Jay Berger, it was a day of wonder, one to be cherished even in defeat. For Heinz Gunthardt, it was a day to cherish a gritty victory. For Chris Evert Lloyd and Hana Mandlikova, it was a day at the office. For Ivan Lendl, it was almost an embarrassing night.

And for James Scott Connors, it was yet another victory against yet another young player in yet another U.S. Open.

That was Day Eight at the U.S. Tennis Center. The most remarkable tennis of the day was, without question, played by Gunthardt and Henri Leconte, who dueled masterfully for more than three hours on the Grandstand Court before Gunthardt came back from the dead for a 7-6 (7-5), 6-2, 3-6, 4-6, 6-3 victory.

The most fun came from watching Berger and Yannick Noah. Berger, 18, a sophomore at Clemson University, played a magnificent first set, then realized where he was and lost to Noah, 6-7 (5-7), 6-2, 6-3, 6-1.

"I lost to Yannick Noah," Berger said. "What am I going to do, slam my racket?"

The most easily predicted tennis came from Evert, who reached the semfinals here for the 15th straight year with a routine 6-3, 6-3 victory over Claudia Kohde-Kilsch. The most surprising tennis came from Mandlikova, who joined Evert with a 7-6 (7-4), 7-5 victory over fellow Czechoslovakian Helena Sukova by playing with the kind of consistency and determination that has eluded her throughout her erratic career.

And the strangest tennis came at night, Lendl playing the first set against 17-year-old Jaime Yzaga as if in a coma before the little (5-foot-5, 135-pound) Peruvian wilted and Lendl managed a 4-6, 6-3, 6-4, 6-0 victory. "The first set I couldn't hit a ball in the court," Lendl said. "I'm just glad to get the match behind me." He gets Noah next.

But the story of this day had to be Connors. He beat 19-year-old Stefan Edberg, 6-4, 3-6, 6-3, 6-4, in slightly less than three hours. Connors is 33 years and a day or so old. Edberg is a rising talent, considered by many the most likely Swede to join Mats Wilander in the top five in the next two years.

Edberg is fluid, graceful, the prototype young player with all the shots. Connors is old, can't serve very hard and should know better than to think he can beat such kids.

"If I'm still beating people out here when I'm 48, then something is definitely wrong," Connors said. "Age is part of tennis. People get older and there comes a time in life when you move on to other things."

Okay, how about 47, Jimmy? "Well . . . "

Connors, the fourth seed here, probably can't win this tournament -- probably. He may even have trouble with Gunthardt in the quarterfinals. But he still is one of the game's great competitors. "I think he's better now than he was five years ago," John McEnroe said recently.

That isn't so. But Connors can still will himself through a match like this one simply because Edberg looks across the court and sees Connors grunting and charging and stoking and thinks he's playing JIMMY CONNORS.

Today, after the two split sets, Edberg broke serve in the first game of the third set when Connors ran down a forehand but netted it. So there was the kid, having just won the second set, having just broken the old man, having all the momentum in the world.

Check that. The old man promptly broke back, hitting one of those screeching backhand returns he invented in 1890 and following that with a forehand pass that the kid could only lunge for vainly: 1-all.

From there, the match belonged to Connors. This was, after all, his spot. Wimbledon has charm and tradition but dusk here, with the sun rolling down the rim of the stadium against the Manhattan skyline, is matchless. And no one has played better or won more -- a men's record 76 Open matches -- against this backdrop than Connors.

And so, every time Edberg challenged, Connors had an answer. He lobbed superbly, constantly frustrating Edberg by landing balls just inside the base line. It was a lob that got Connors the break he needed in the third set. Edberg chased the ball down but his desperate backhand flew wide as Connors pointed his finger as if guiding it wide.

"I've been in a slump for a while but I think I'm coming out of it," said Connors, who has not won a tournament this year. "But I'm playing better now, moving better, hitting the ball better."

Actually, Connors is doing just what he has been doing most of the year: beating everyone in the world not named McEnroe, Lendl or Wilander. Tonight, after he saved five break points to win the third set, he got a quick break in the fourth and served out the match.

"The thing I'm proudest of about my tennis over the year is the way I've played here," Connors said. "The matches I've won, the people I've beaten, the times I've won when I wasn't supposed to."

As for today's other winners, the most deserving was certainly Gunt-hardt. Leconte, a quarterfinalist at the French Open and at Wimbledon, is the most eccentric player in the game today. He is going to destroy someone out there, the only question is whom.

Today, for two sets, it was self-destruct. Gunthardt, an underrated Swiss who also made the quarters at Wimbledon, makes few mistakes. Leconte made his in bunches and was quickly two sets in the hole. But then the other Leconte showed up. This one blasts winners from everywhere, whacks topspin a' la Borg and electrifies a crowd with his brilliance.

For two sets and a little more, that was Leconte. He broke Gunt-hardt in the eighth game of the third set with a sequence so superb it sent chills down the spine. First, a running topspin forehand down the line. Then, a rocket backhand return. Then, a pickup volley and a crunching overhead. Finally, a running forehand for the game that Leconte saluted with a Connors-style pumping motion and quick turn and jump.

That game set the tone for the rest of the match. Gunthardt, normally rather placid, got caught up in it, pumping his fist little himself and hitting some great shots, too. In the fourth set, Gunthardt saved one break point with a lunging volley, then cracked a backhand cross court and a game-closing reach volley.

Leconte, having thrown his racket at the last winner, stopped and applauded Gunthardt. As the men walked to their chairs, Leconte playfully swiped at Gunthardt's racket as if to say, "Cut that out!" The crowd cheered both.

After Leconte won the fourth set with a flurry of winners, he immediately broke Gunthardt to start the fifth and had another break point leading 2-0. Gunthardt changed up on his serve on that point, giving Leconte a slow ball, which he netted.

From that moment on, the match changed. Gunthardt never lost another point on his serve and suddenly Leconte began missing.

Both men were a class act today.

So were Evert and Mandlikova. After disastrous Grand Slam performances in the French and Wimbledon, Mandlikova, sporting a new short haircut, has not lost a set here. Today, she played a superb first-set tie breaker and hit four winners at 6-5 in the second.

Finally, Evert. Fifteen Opens, 15 semifinals. "This was a good, tough match for me," Evert said.

Uh-huh. Undoubtedly, 20 years from now when she and Connors are still playing in this tournament -- and still winning -- she will say the same thing.