Moscow, Russia -- (Sports Network) - Two-time defending champion Nikolay Davydenko and two-time major titlist Marat Safin highlighted Tuesday's first- round winners at the $1.049 million ATP Kremlin Cup.

The top-seeded Davydenko handled France's Florent Serra 6-1, 7-5 to continue his winning ways at this event, where he has won three out of the last four titles on the indoor carpet at Olympic Stadium. The Russian star topped Frenchman Paul-Henri Mathieu in last year's finale.

Up next for Davydenko will be Spaniard Guillermo Garcia-Lopez.

The seventh-seeded former world No. 1 Safin barely held off Israeli qualifier Noam Okun 7-6 (7-5), 3-6, 6-4 for his 400th career win. Safin will face Frenchman Julien Benneteau in the round of 16.

An upset came when Uzbekistani qualifier Denis Istomin ousted sixth-seeded Frenchman Michael Llodra 7-6 (7-2), 6-3, while eighth-seeded Serb Janko Tipsarevic avoided an early exit with a 4-6, 6-3, 7-6 (8-6) decision against Russian wild card Alexandre Kudryavtsev.

In other Day-2 action, Serbian Viktor Troicki drubbed Russian wild card Evgeny Donskoy 6-1, 6-3; the aforementioned Benneteau handled Israeli qualifier Harel Levy 6-4, 6-3; Israeli Dudi Sela stopped Romanian Victor Hanescu 6-3, 3-6, 6-2; and American Robby Ginepri grounded Czech qualifier Jiri Vanek 6-3, 6-4.

The 2008 Moscow champ will collect $171,000.