WIMBLEDON, England (AP) _ Anna Kournikova overcame three set points in the opening set and defeated Maria Alejandra Vento 7-5, 6-4 today in the second round at Wimbledon.

Kournikova, seeded 17th, is one victory away from a potential fourth-round match against No. 6 Venus Williams. The 18-year-old Russian reached the semifinals in her only other appearance at Wimbledon in 1997.

As usual, the photogenic teen-ager attracted a horde of zoom lenses for her match on Court 2. She trailed Vento 4-5, 0-40, then won the next eight points to take charge and raced to a 4-1 lead in the second set.

The victory improved Kournikova's record at the All England Club to 7-1.

Amanda Coetzer, seeded 12th, also reached the third round by beating Miho Saeki 6-4, 6-1. No. 13 Sandrine Testud eliminated Barbara Rittner 7-6 (7-2), 6-1.

All 16 seeded men reached the second round. The last to advance was Tommy Haas, who completed a victory Wednesday over Peter Wessels, 3-6, 6-4, 4-6, 6-3, 6-4. The match was suspended because of darkness after four sets Tuesday.

French Open runnerup Andrei Medvedev was eliminated in the second round by Daniel Nestor, 6-1, 7-5, 6-3.

The only first-round upset on the women's side ranked with the greatest shockers in Wimbledon history. No. 1 Martina Hingis was drubbed Tuesday 6-2, 6-0 by Jelena Dokic, a 16-year-old qualifier ranked 129th.

The match was Hingis' first since an emotional loss in the French Open final that left her sobbing on her mother's shoulder.

``I think she's devastated by the French Open fiasco,'' said six-time Wimbledon champion Billie Jean King, a commentator for HBO. ``I think it's taken a lot out of her. She doesn't have her equilibrium back. She looks emotionally crushed.''

It was only third time the No. 1 women's seed has been eliminated in her opening match at Wimbledon, and also the third time during the Open era that a top women's seed has lost her opening match at a Grand Slam event.

``It happens to everybody sometimes,'' Hingis said. ``I'm not that disappointed.''

On the men's side, Boris Becker came back from two years off and two sets down.

The three-time Wimbledon champion returned to his favorite tournament Tuesday and barely avoided a hasty exit. Becker overcame three match points in the fourth set and rallied past wild-card Miles Maclagan 5-7, 6-7 (7-9), 6-4, 7-5, 6-2.

The match was Becker's first in a major tournament since he announced his retirement from Grand Slam competition following a quarterfinal loss to Pete Sampras at Wimbledon two years ago. Becker, 31, changed his mind but swears that this Wimbledon really, truly will be his last.

``I'm still around, somehow,'' he said.

Just barely. Becker's first-round victory was so harrowing that his wife, Barbara, left before the match ended. She's expecting their second child in mid-August.

``She was getting very excited toward the end of the fourth set,'' Becker said. ``I turned to her and I told her to be quiet, to calm down a little, because otherwise we have a baby on the court. The more excited she gets, the earlier my second one is coming.''

Other winners Tuesday included No. 2 Patrick Rafter, No. 4 Andre Agassi and No. 5 Richard Krajicek. All won in straight sets.

Becker survived a four-hour marathon against Maclagan, a Briton ranked 298th. Becker saved the first match point with an ace, one of 31 he hit, and saved the final match point with another big serve.

After pulling out the fourth set, Becker pulled away in the fifth. He improved to 69-11 at Wimbledon, including 9-2 in five-set matches.