Former world No. 1 Juan Carlos Ferrero was a first-round upset victim Tuesday at the Croatia Open tennis event.

Croatian wild card Mate Pavic upended the sixth-seeded Ferrero 6-2, 6-2 on the red clay at ATP Stadium. The former French Open champion Ferrero was the Umag titlist in 2010 and runner-up in 2009.

Fifth-seeded Argentine Carlos Berlocq avoided an upset by besting Croat Ivan Dodig, 6-4, 6-0.

Another upset occurred when American Wayne Odesnik drove out eighth-seeded Frenchman Edouard Roger-Vasselin 6-7 (4-7), 6-2, 7-5.

Additional opening-round wins came for Latvian Ernests Gulbis, German Daniel Brands, Slovenian Blaz Kavcic, Italians Fabio Fognini and Potito Starace, and Argentine qualifier Marco Trungelliti. Starace was the runner-up here in 2010.

The top seeds here are Spanish lefthander Fernando Verdasco, the 2008 Umag champion, and Croat Marin Cilic, who was last year's runner-up to Ukrainian Alexandr Dolgopolov. Verdasco will open his week against Gulbis, while Cilic will encounter Brands in the second round.