World No. 88 Lukas Rosol of the Czech Republic dumped sixth seed Denis Istomin out of the Kremlin Cup on Wednesday in a hard-fought three-set match.
Istomin, a 2010 semifinalist, took the first set before Rosol stormed back to win the next two without giving a single break point to his opponent for a 4-6, 6-4, 6-3 win.
The Kazakh nation who resides in Moscow became the second seeded player to fall in the men’s draw after three-time champion Nikolay Davydenko, seeded fifth, was knocked out by Alex Bogomolov in the first round.
The 27-year-old Rosol, who was eliminated in the first round last year, will now encounter either reigning champion Viktor Troicki of Serbia or Malek Jaziri of Tunisia, who clash later Wednesday.
Elsewhere, Ivo Karlovic defeated Simone Bolelli of Italy 6-4, 7-6(4) while, tournament newcomer Poland’s Jerzy Janowicz beat world No. 80 Benjamin Becker of Germany 7-6(6), 6-3.
The Polish 22-year-old will play seventh seed Carlos Berlocq of Argentina in the second round.
Earlier, Japanese eighth seed Ito Tatsuma dispatched qualifier Konstantin Kravchuk of Russia 7-6(7), 2-6, 6-3.