The $708,000 hard-court event in New Haven, Conn., is a final tune-up before the U.S. Open begins play next Monday in New York
Another first-round winner at Pilot Pen was Belgian Steve Darcis, who beat American Vincent Spadea, who lost the first set and then retired after trailing 5-0 in the second.
German Denis Gremelmayr dropped his first set against Brazilian Marcos Daniel 3-6 but regained his footing and took the next two 6-3, 6-3.
Another Belgian, Olivier Rochus, ousted Russian Evgeny Korolev 6-4, 6-4, while Italian Potito Starace defeated Czech Jiri Vanek 6-2, 7-6 (9-7).
Spaniard Guillermo Garcia-Lopez eliminated Australia's Chris Guccione 7-5, 6-3 and Italian Fabio Fognini emerged a winner when Ecuador's Nicolas Lapentti retired at 4-4 in the second set after losing the first set 6-4.
Last year's champion, American James Blake, is not competing in this year's edition.