Geneva, Switzerland (SportsNetwork.com) - Santiago Giraldo and Andrey Rublev were first-round winners Sunday at the Geneva Open, a final clay-court French Open tune-up.

Giraldo of Colombia outlasted Lithuanian Ricardas Berankis 6-3, 6-7 (5-7), 6-3, while Rublev of Russia beat Jarkko Nieminen of Finland 6-3, 6-7 (4-7), 7-6 (7-4).

The Geneva Open returns to the ATP World Tour for the first time since 1991. Leading the way in the field are two of last year's Grand Slam champions, Stan Wawrinka (Australian Open) and Marin Cilic (U.S. Open), who are No. 9 and No. 10, respectively, in the Emirates ATP Rankings.