Simon loses at Mercedes Cup tennis

STUTTGART, Germany, July 16 (UPI) -- Top-seeded Gilles Simon lost in the second round Thursday to unheralded Mischa Zverev at the Mercedes Cup tennis tournament in Stuttgart, Germany.

The 21-year-old Zverev, the world's 45th-ranked men's tennis player, topped the seventh-ranked Simon 6-4, 6-2 by converting 3-of-8 break point chances and saving the five break points he faced.

A native of Hamburg next faces another Frenchman, Jeremy Chardy, in Friday's quarterfinals.

Chardy topped Argentina's Martin Vassallo Arguello 2-6, 6-3, 6-1.

Elsewhere, Russian Nikolay Davydenko, the second seed, ousted Germany's Michael Berrer 6-3, 6-3; Italian Fabio Fognini topped France's Paul-Henri Mathieu 6-4, 4-1, with Mathieu retiring in the second set because of dizziness; while German Nicolas Kiefer downed countryman Simon Greul 6-3, 6-4.

A key match at Friday's quarterfinals pits Davydenko against Fognini.