Top-seeded Gilles Simon of France and Germans Philipp Kohlschreiber and Nicolas Kiefer were winners Tuesday at the Mercedes Cup in Stuttgart, Germany.

Simon defeated German Philipp Petzschner 6-3, 6-4. Kohlschreiber, seeded fifth, defeated Argentine Diego Junqueira 6-3, 6-2. Unseeded Kiefer upset third-seeded Czech Tomas Berdych 6-3, 6-3.

Two other seeds also lost Tuesday. Italian Fabio Fognini beat seventh-seeded Frenchman Fabrice Santoro 5-7, 7-6 (7-3), 6-1 and France's Jeremy Chardy beat eighth-seeded Argentine Jose Acasuso 6-2, 7-6 (7-4).

Also, German Rainer Schuettler outlasted Czech Ivo Minar 2-6, 7-6 (7-2), 6-4; and German Simon Greul defeated countryman Andreas Beck 7-6 (7-4), 7-6 (7-5).