Top-seeded Henri Leconte of France and second-seeded Jakob Hlasek of Switzerland Thursday advanced to the quarterfinals of the $490,000 Belgian Indoor Championship at Brussels.
Fourth-seeded John Fitzgerald of Australia and Patrick Kuhnen of West Germany also advanced.
Leconte defeated Eduardo Masso of Belgium, 6-3, 6-4, but Hlasek had to rally to edge American Glenn Layendecker, 4-6, 7-6, 6-4.
Kuhnen beat Christian Saceanu of West Germany, 6-3, 7-6, and Fitzgerald edged Karel Demuynck of Belgium, 6-4, 6-4.
Leconte, ranked No. 13 in the world, will play eighth-seeded Wally Masur of Australia in one quarterfinal match, and Hlasek, who has won his last two tournaments, will play Tom Nijssen of the Netherlands in another.
Fitzgerald will meet Eric Jelen of West Germany and Kuhnen will play Eric Winogradsky of France.