THE SIDELINES : Mayotte Reaches Moscow Semis

Tim Mayotte beat fifth-seeded Alexander Volkov, 6-3, 6-2, today to advance to the semifinals of the Kremlin Cup on a day that tennis fan Boris Yeltsin made a guest appearance.

Yeltsin, the popular president of the Russian Federation--the largest of the 15 Soviet republics--arrived while Andrei Cherkasov was beating Emilio Sanchez of Spain, 6-3, 6-3. The audience of 13,000 applauded when Yeltsin’s arrival was announced and he responded by standing and waving with a smile.

Cherkasov, asked if Yeltsin’s arrival influenced his play, said: “I am from Russia and I wanted to win in this situation. And I’m happy that I won.”

In other matches, Peter Korda of Czechoslovakia beat Anders Jarryd of Sweden, 7-5, 7-6, and Udo Riglewski of Germany beat Sergio Casal of Spain, 4-6, 7-6 (8-6), 6-3, in 2 hours, 49 minutes.