Nice, France (SportsNetwork.com) - Second seed John Isner highlighted Tuesday's winners at the Nice Open, a final clay-court French Open tune-up.

The 6-foot-10 star swatted 16 aces and held off fellow American Steve Johnson 7-6 (7-3), 4-6, 6-3 on the red clay at Nice Lawn Tennis Club.

Another second-round result saw eighth-seeded Argentine Juan Monaco maul American Sam Querrey 6-3, 6-1.

In some opening-round action involving seeds, French qualifier Gianni Mina toppled No. 5 Aussie Bernard Tomic, who retired after dropping the first set 6-2, No. 6 Aussie Nick Kyrgios beat Kazakhstan's Mikhail Kukushkin 7-6 (7-5), 6-2, and Serb Dusan Lajovic tackled No. 7 American Jack Sock 5-7, 7-5, 6-1.

Additional first-round wins came for Aussie James Duckworth, Ukrainian Alexandr Dolgopolov and French wild card Lucas Pouille, who whipped American Tim Smyczek 6-3, 6-0. Duckworth took out lucky loser promising American Francis Tiafoe, 6-7 (5-7), 7-5, 6-2.

In some more second-round action here on Wednesday, top-seeded Frenchman Gilles Simon will face Duckworth and third-seeded reigning Nice champ Ernests Gulbis will encounter Dolgopolov.

Gulbis beat Argentine Federico Delbonis in last year's Nice finale.