Updated

Winston-Salem, NC (Sports Network) - American qualifier Steve Johnson upset Italian No. 2 seed Andreas Seppi 6-7 (5-7), 6-4, 7-5 in Tuesday's second-round action at the Winston-Salem Open, a final hardcourt U.S. Open tune-up.

The 23-year-old Johnson defeated countryman Bobby Reynolds on Monday and won only his fourth match of the year (4-8). It was just his third time winning back-to-back matches in his career.

No. 4 seed Tommy Robredo of Spain upended Frenchman Guillaume Rufin, 7-6 (7-5), 4-6, 6-3, while fifth seed Benoit Paire took care of aging American James Blake. The Frenchman Paire held off the 33-year-old Blake 7-6 (11-9), 2-6, 6-3 on the grounds at Wake Forest University.

Seventh-seeded Spanish left-hander Fernando Verdasco reached the third round by overcoming American Tim Smyczek, 3-6, 6-3, 6-3.

Eighth-seeded Argentine Juan Monaco overcame France's Nicolas Mahut 6-7 (4-7), 6-3, 6-4; ninth-seeded Austrian Jurgen Melzer was beating Thiemo de Bakker 7-5, 6-7 (4-7), 4-2 when the Dutch qualifier retired in the third set; and 10th seed Alexandr Dolgopolov ousted Daniel Gimeno-Traver, 4-6, 6-1, 6-4.

Eleventh-seeded Finnish veteran Jarkko Nieminen was leading health-challenged American Mardy Fish 7-5, 6-7 (3-7), 3-2 when the wild card Fish retired on Day 3, citing heat stroke. The former Top-10 star Fish has missed substantial time on the tour over the last two seasons due to a heart condition.

In other action, 13th-seeded Russian Dmitry Tursunov overcame Belgian qualifier David Goffin 4-6, 7-5, 6-1; Spaniard Roberto Bautista Agut ousted 14th-seeded Slovak Martin Klizan 6-4, 6-1; and No. 15 seed Gael Monfils beat Guido Pella, 6-2, 6-2.

In some second-round play not involving seeds, Lithuanian Ricardas Berankis topped American lucky loser Denis Kudla 6-4, 6-4 and Russian Alex Bogomolov Jr. defeated Portuguese lucky loser Joao Sousa 6-4, 6-1.