LONDON, JUNE 22 -- It had been 18 years since the opening day at Wimbledon was washed out entirely. Until today.

It never rained that hard, and for brief spells it didn't rain at all, but the day wasn't uneventful: for starters, the tournament's fourth seed, Hana Mandlikova of Czechoslovakia, withdrew because of an injured heel.

It rained just enough so that the courts stayed covered all day while players crowded into the tea room, spectators huddled under umbrellas and the committee kept up a steady stream of optimistic announcements about the clearing skies that never came.

Finally, at 6:30 p.m., tournament director Christopher Gorringe announced that "regretfully, we must abandon play for the day." The news was especially regretful to the 24,000 ticket holders who showed up and waited all day without seeing a ball hit. Wimbledon has a no-refund, no-raincheck policy.

That one piece of significant news came shortly after play was called off.

Mandlikova, last year's losing finalist, said through a spokesman that she had aggravated an injury to her right heel that has bothered her all spring.

She is returning to Czechoslovakia for treatment, and, if that fails, possible surgery.

Her departure caused a shuffling in the women's draw that should help Chris Evert and Martina Navratilova. Helena Sukova, the fifth seed, was moved to No. 4 -- and into the lower half of the draw.

That means Evert is now seeded to face Claudia Kohde-Kilsch in the quarterfinals, rather than Sukova, with the winner probably playing Navratilova in the semifinals.

Sukova beat both women last weekend at Eastbourne. She now moves into the same quarter as Pam Shriver and the same half as Steffi Graf.

In another off-the-court development, the Women's International Tennis Association announced that, should Graf win Wimbledon, she will replace Navratilova as the No. 1 player on the rankings computer.

Given that in the 12-year history of the women's computer either Navratilova or Evert has been No. 1 for all but a brief period in early 1980 when Tracy Austin held the spot, this was news on a rainy day.

The rain was hardly a surprise. It has rained here for 21 of 22 days in June and the forecast for the rest of the week isn't much better. With no matches to watch, people were left to their own devices for entertainment.

Some players went off in search of indoor practice courts. Boris Becker, who was scheduled to play the first match on Centre Court, stayed on the grounds, partly because his match is scheduled first and partly because he was still reeling slightly from blaring headlines in this morning's London tabloids about his being snubbed by several private clubs when he went looking for practice time on Sunday.

The tabloids, naturally, were getting a lot of attention. The tournament committee put out an announcement banning personal questions during the postmatch interviews.

This came after Navratilova and Evert were the subject of headlines involving their respective off-the-court lives the last two days.

But for the most part, boredom was the rule of the day. Ivan Lendl, after spending some time in the player's tea room, retreated to the locker room where he and his coach, Tony Roche, watched a BBC replay of his loss in last year's final to Becker.

Finally, there was the ultimate piece of rainy-day news: Before the tournament began, London bookmakers were giving 33-to-1 odds on at least one rain delay each of the 13 days of the tournament.

By this evening, the odds were down to 28-1. TODAY'S FEATURED MATCHES Centre Court

Boris Becker (1), West Germany, vs. Karel Novacek, Czechoslovakia; Pat Cash (11), Australia, vs. Marcel Freeman, Los Angeles; Mikael Pernfors, Sweden, vs. Robert Seguso, Sebring, Fla. Court 1

Christian Saceanu, West Germany, vs. Ivan Lendl (2), Czechoslovakia; Gabriela Sabatini (7), Argentina, vs. Barbara Gerken, Calabassas, Calif.; Tim Mayotte (10), Bradenton, Fla., vs. Jean-Philippe Fleurian, France. Court 2

Stefan Eriksson, Sweden, vs. Stefan Edberg (4), Sweden; Stuart Bale, Britain, vs. Brad Gilbert (12), Piedmont, Calif.; Mats Wilander (3), Sweden, vs. Gary Muller, South Africa. Court 4

Marie-Christine Calleja, France, vs. Lori McNeil (11), Houston; Mike Bauer, Lafayette, Calif., vs. Emilio Sanchez (14), Spain. Court 13

Joakim Nystrom (13), Sweden, vs. Henrik Sundstrom, Sweden; Helen Kelesi, Canada, vs. Manuela Maleeva (8), Bulgaria; Sergio Casal, Spain, vs. David Pate (15), Las Vegas.