Rajeev Ram of the United States and Serbia’s Nenad Zimonjic won the men’s doubles tournament at the St. Petersburg Open on Sunday.

The top-seeded American-Serbian tandem overpowered Slovakians Lukas Lacko and Igor Zelenay 6-2, 4-6, 10-6 in a tense final.

Zimonjic, 36, is now a three-time doubles winner in St. Petersburg after first claiming the prize in 2003 with Austria’s Julian Knowle and then in 2007 with Daniel Nestor of Canada.

The singles final between Martin Klizan of Slovakia and Italian Fabio Fognini is later Sunday.

The prize fund for the tournament is over $410,000.