LONDON, JULY 2 -- Larisa Savchenko and Svetlana Parkhomenko, of the Soviet Union, pulled one of the biggest upsets of recent Wimbledons this evening when they beat defending champions Martina Navratilova and Pam Shriver, 6-2, 6-4, to advance to the women's doubles semifinals.

The Soviet pair were certainly aided by the fact that Navratilova played a draining two-hour singles match today and the fact that Shriver, while only playing 50 minutes of singles today, had played marathon matches the previous two days.

But that did not diminish the magnitude of the upset. Navratilova-Shriver had won five titles in six previous Wimbledons, losing the final the other year. They have won 16 Grand Slam titles together and the last four in a row, beginning with Wimbledon last year. The victory was easily the biggest for Savchenko-Parkhomenko, who were seeded sixth. They will meet Claudia Kohde-Kilsch and Helena Sukova in the semifinals.

By winning, the Soviets continued the excellent performance by their country at this Wimbledon. In singles, Natalia Zvereva and Alexander Volkov reached the fourth round and Zvereva, 16, today easily advanced to the quarterfinals of the junior championships.

The loss also means Shriver and Navratilova will not be able to complete a calendar Grand Slam. They had already won the Australian and French Opens this year.

In men's doubles, Ken Flach and Robert Seguso of the United States, the consummate doubles team for several years, beat top seeds Yannick Noah and Guy Forget in a classic five-set quarterfinal.

There was irony in the victory since it was against Noah and Henri Leconte that they won the Open final in '85 after the French accused Flach of "cheating" on a crucial point when they claimed a ball had clipped his hair before going out. -- John Feinstein RESULTS Women's singles Semifinals

Martina Navratilova (1), Fort Worth, def. Chris Evert (3), Boca Raton, Fla., 6-2, 5-7, 6-4; Steffi Graf (2), West Germany, def. Pam Shriver (5), Lutherville, Md., 6-0, 6-2. Women's doubles Quarterfinals

Svetlana Parkhomenko-Larisa Savchenko (6), Soviet Union, def. Martina Navratilova-Pam Shriver (1), U.S., 6-2, 6-4; Claudia Kohde-Kilsch, West Germany-Helena Sukova (3), Czechoslovakia, def. Kathy Jordan-Anne Smith, U.S. (9), 7-6, 7-5. Men's doubles Quarterfinals

Stefan Edberg-Anders Jarryd (4), Sweden, def. Carl Limberger-Mark Woodforde, Australia, 6-3, 3-6, 6-3, 6-4; Andres Gomez, Ecuador-Slobodan Zivojinovic (3), Yugoslavia, def. Darren Cahill-Mark Kratzmann, Australia, 2-6, 7-6, 6-7, 7-6, 7-5; Ken Flach-Robert Seguso (7), U.S., def. Guy Forget-Yannick Noah (1), France, 7-6 (7-4), 4-6, 4-6, 6-3, 6-4. Mixed doubles Quarterfinals

Sergio Casal, Spain-Raffaella Reggi, Italy, def. B.C. Buffington, U.S.-Nicole Jagerman, Netherlands, 6-1, 3-6, 6-1.TODAY'S FEATURED MATCHES Centre Court

Ivan Lendl (2), Czechoslovakia, vs. Stefan Edberg (4), Sweden: Jimmy Connors (7), Sanibel Harbor, Fla., vs. Pat Cash (11), Australia.