It is better to have learned and lost than not to have learned at all. Wally Masur lost to Jimmy Connors today, 6-4, 7-6 (8-6), 6-0, and said, "I'm grateful for the experience. I found out what I have to do. I found out he's not unbeatable."

One thing Masur has to learn is not to squander two set points, as he did in the second set tie breaker. Connors, who rarely concedes anything, conceded it wasn't a "10" performance for him, but his interest now that he has passed the dangerous first round is simply in improving his level of play, day by day, as he says you must at Wimbledon.

Masur thought Connors wasn't hitting the ball as well as he can. But, he said, "He's all over you like a a terrier. He never makes a dumb shot or gives away an easy point. He always make the return. He's tenacious once he gets a hold of it."

Connors, the defending champion, is expected to win matches like that. Others like Nduka (Duke) Odizor, who unexpectedly eliminated Guillermo Vilas Monday, won again, defeating Peter Fleming, 6-4, 4-6, 6-4, 6-2. Rodney Harmon of Richmond served and volleyed and looked at home beating Brad Drewett, 6-2, 6-4, 6-4.

But the best match of the day began Tuesday, was halted by darkness and resumed this afternoon with Mats Wilander, the No. 5 seed, beating John Fitzgerald, 6-4, 6-1, 4-6, 6-7, 6-4. Wilander had been just as glad to call it a day with the match tied at two sets each. He had wasted five match points in the fourth set, then darkness came but not gloom.

Wilander, the Swedish base-liner who is trying to make the adjustment to grass that Bjorn Borg made before him, came back and played his best match ever on grass.

His passing shots are still his strength, but he says he is learning to serve and volley. The fifth and final set was tautly played. They traded breaks in the fifth and sixth games and stayed even, 4-4. In the ninth game, Wilander gained a break point with a forehand down the line that Fitzgerald could not handle. On break point, Fitzgerald netted a backhand volley to give him the game.

Wilander served out the set and when Fitzgerald netted a forehand that hit the tape to give him match point, Wilander bent and kissed the net ever so gently.

"I think I played as well as I could on grass," Wilander said. "I still have to improve my first serve and volley. . . sometimes it comes naturally. When I'm leading and confident it comes naturally. But in a tough situation like in the last game of the fifth set, I have to force myself."

That, of course, is what it's all about.