The Czech Republic's Rosol was upended by German Daniel Brands 6-4, 6-3 on the red clay at Rochusclub in Day 1 of the new event, a final tuneup for the French Open.
Next up for Brands will be Czech Jan Hajek, who dispatched Russian Evgeny Donskoy in another first-round match.
Croatia's Ivan Dodig eliminated Slovenia's Blaz Kavcic 7-5, 6-4 Sunday.
N.J. man wakes up from 10-hour sleep with knife in back
Sign language interpreter at Mandela service called out as fake on Twitter