Kitzbuhel, Austria (Sports Network) - Last year's runner-up Potito Starace and last week's Stuttgart champion Juan Martin Del Potro were a pair of quarterfinal winners, while Wimbledon semifinalist Rainer Schuettler failed to win two matches Friday at the clay-court Austrian Open.

The fourth-seeded Starace drilled fifth-seeded Argentine Eduardo Schwank 6-1, 6-2, while the seventh-seeded Del Potro remained red hot with a 6-2, 6-3 decision against France's Nicolas Devilder in the quarters and a 6-2, 6-4 victory over fellow Argentine Sergio Roitman in the second round. Del Potro was forced to complete two matches on Friday after rain wreaked havoc on the schedule here on Thursday. The Italian Starace lost to Argentine Juan Monaco in last year's Kitzbuhel finale. Del Potro captured his first-ever ATP title last week in Stuttgart.

A second-seeded Schuettler, meanwhile, won his second-rounder on Day 5 but dropped his quarterfinal at the hands of sixth-seeded Austrian crowd favorite Jurgen Melzer, 2-6, 7-5, 7-5. The German Schuettler got past Czech Jan Hernych 2-6, 6-4, 7-5 to open his day at Sportpark.

Romanian Victor Hanescu won his eighth straight match by handling Argentine Brian Dabul 6-3, 6-4. Hanescu, like Del Potro, became a first-time ATP champion last week, by titling in Gstaad.

One other Friday result saw the aforementioned Devilder drop Austrian Alexander Peya 6-4, 6-4 in a second-round affair.

Saturday's semifinals will pit Starace against Melzer and Del Potro versus Hanescu.

The 2008 Kitzbuhel titlist will claim $185,000.