PARIS, JUNE 10 -- While 16-year-old Monica Seles got giddy on champagne, Steffi Graf canceled a party in the aftermath of their French Open final. Graf lost a measure of self-assurance when she was beaten by Seles in straight sets, and you could almost sense it passing into the teenager who has so upset the balance of power in women's tennis.

Graf left Paris hastily, questioning her confidence and seeking the solitude of her home in Bruhl, West Germany, after Seles defeated her, 7-6 (8-6), 6-4, at Stade Roland Garros Saturday. The No. 1-ranked and most-dominant player of her generation had a rare, stricken demeanor, and it was because she now has been stunned twice by the left-handed Seles in straight sets over the last month.

No. 3 Seles became the youngest female French Open champion, surpassing Arantxa Sanchez Vicario's feat in upsetting Graf at age 17 last year. Seles has won six straight tournaments covering 32 matches, and she is the first to defeat Graf twice in a row since Gabriela Sabatini did so in 1988, winning two Florida tournaments when Graf had a cold.

The West German could only cling to the thought that she had recovered from last year's loss here by claiming the 1989 Wimbledon and U.S. Open titles. Her plans were to take just a couple of days off before going to the grass courts of the All England Club.

"I hope I cope the same way," she said.

But there are vast differences between this season and last. Then, Graf still was largely invincible, going on to win 66 straight matches. Now, Seles is on a streak in which she defeated No. 2 Martina Navratilova in the Italian Open final, beat Graf in the German Open final three weeks ago, and claimed her first Grand Slam title when Graf uncharacteristically lost four set points in their tiebreaker and had her serve broken five times.

Graf was at a loss to explain her lack of ruthlessness against this girl who doesn't even have a driver's license, and who dashed across Paris Saturday night in dangling gold earrings and gales of laughter from her first sips of champagne. Seles slipped out of the tiebreaker like an escape artist wriggling out of handcuffs, lashing a series of winners. Graf lost the fourth of her set points with a double fault.

"I don't think you can really lose your tennis," Graf said. "It is impossible. You cannot lose your forehand or your backhand. I just didn't feel sure with my shots."

Seles had announced her presence to Graf in last year's French Open semifinals by extending her to three sets before losing. So Saturday's victory was perhaps a logical if unforseen progression. The thought that Seles has shot to No. 3 and from 5 feet 5 and 95 pounds to 5-9 and 125 in just a year hardly was consoling.

"I knew I was close to her even last year," Seles said. "This is where it started for me. But at 15 I didn't think I could beat her, physically or mentally, since I wasn't as strong. I was missing a couple of strokes that I have now."

Seles has pace that is nearly Graf's equal; the West German hits a heavier ball, but the Yugoslavian strikes a faster one. Seles also has a dead aim at the lines and finds peculiar angles with her two-fisted strokes, both forehand and backhand. If the sprinter-like Graf appeared strangely slow and ill-prepared, it is because Seles has discovered a couple of technical weaknesses in her game.

Graf derives forehand power from whip-like racket speed off her hip. But she is late taking the racket back, and Seles' rocketing pace jams her in midswing and can cause wild errors. Graf never has been as comfortable on the backhand side, relying on a less harmful low slice that Seles reaches easily. Graf rarely risks hitting over the ball, and it is interesting to note that she has been experimenting with a two-handed backhand in practice, perhaps trying to find a more aggressive shot.

"You really have to go for your shots and hit them early," Graf said. "I hit them late. I need to be more relaxed."

Graf's task now is not to only find some solution to Seles' troubling game, but regroup internally. Seles could sympathize. She experienced how fine a difference there is between having it and losing it when she suffered three straight upsets to begin the season, including a first-round loss in Chicago.

"It's something you feel inside and maybe she is not feeling it," Seles said. "At the beginning of the year I wasn't feeling it either. Only the person can tell, the opponent can't realize it."

Graf's problem may be solved simply by switching to grass courts, on which her pace is more lethal than on the red clay that makes her so ill at ease. It perhaps is telling that Graf brought Seles to tears at last year's Wimbledon, with a 6-1, 6-0 rout.

"On grass it will be different for sure," Graf said. "I can do better."

But, frighteningly, so can Seles. She planned to reward herself with tickets to a couple of World Cup soccer matches in Italy and three or four days of vacation to recover from an exhausting stretch of tennis. Yet she already has thoughts of Wimbledon and the wrinkles she intends to add to her game. "I have to get totally recycled," she said.

Seles' serve has improved but can develop into even more of a weapon, and so can her seldom-used volleys. A serve-and-volley game would seem to be a natural addition since doctors have said she may grow as tall as six feet.

"I still have a lot of growing up to do," she said. "I can improve on a lot of things, like my serve. If I could have served better it would have been a much easier match for me. I can still get better in my ground strokes, my game, everything. That is what I believe in."

Women's Doubles

Top-seeded Jana Novotna and Helena Sukova moved halfway to a Grand Slam today by winning the women's doubles, 6-4, 7-5, over defending champions Natalia Zvereva and Larisa Savchenko, seeded fourth.