Updated

Moscow, Russia (SportsNetwork.com) - Sixth-seeded Argentine Horacio Zeballos was among Monday's opening-round winners at the $750,000 Kremlin Cup tennis event.

Zeballos, who shocked the great Rafael Nadal in a final in Chile earlier this year, came from behind to beat Lithuanian Ricardas Berankis 1-6, 6-3, 6-4 on the indoor hardcourts at Olympic Stadium.

An upset came when Ukrainian Sergiy Stakhovsky upended seventh-seeded Portuguese Joao Sousa 6-4, 6-3.

Also on Monday, France's Edouard Roger-Vasselin snuck past Czech Jiri Vesely 6-3, 6-7 (3-7), 6-3 and Russian wild card Karen Khachanov outlasted Spaniard Albert Ramos 6-2, 3-6, 6-4.

This week's top seeds are U.S. Open semifinalist Richard Gasquet and reigning Moscow champion Andreas Seppi, who beat Brazilian Thomaz Bellucci in last year's finale.

The 2013 Moscow titlist will collect $134,800.