Jurgen Melzer upsets 9th-seeded John Isner at Italian Open

Ninth-seeded John Isner was upset by 64th-ranked Jurgen Melzer 7-6 (7), 6-3 in the first round of the Italian Open on Sunday, eliminating the lone American from the men's event.

Also Sunday, 16th-seeded Tommy Robredo held off Juan Monaco of Argentina 7-6 (3), 6-4; and Philipp Kohlschreiber of Germany outlasted big-hitting Jerzy Janowicz 4-6, 7-6 (6), 6-2.

Jeremy Chardy of France beat Robin Haase of the Netherlands 6-4, 6-4 and will next face Roger Federer, who is expected to be back on tour following the birth of twin sons.

Second-seeded Novak Djokovic will meet Radek Stepanek, the Czech veteran who rallied past Pablo Andujar of Spain 5-7, 6-3, 6-4.

The women's tournament begins on Monday with Serena Williams as defending champion.

Caroline Wozniacki, a former top-ranked player, withdrew due to a knee injury.