Fourth-seeded Spaniard Rafael Nadal and unseeded American John Isner won their respective semifinal matches Saturday at the $3 million Western & Southern Open, a hardcourt ATP Masters 1000 event.

Nadal ran his record on hardcourts this season to 14-0 with a 7-5, 7-6 (7-4) triumph over sixth-seeded Tomas Berdych at the Lindner Family Tennis Center. The 12-time Grand Slam champion improved his head-to-head record against Berdych to 15-3.

The 27-year-old Nadal, who rallied for a three-set win over defending Cincy champ Roger Federer in the marquee match Friday, improved to 15-1 against Top 10 opponents this season as well.

Nadal, last week's Masters champion in Montreal, will take on Isner in Sunday's title match. Isner rallied past seventh-seeded former U.S. Open champ Juan Martin del Potro by a 6-7 (5-7), 7-6 (11-9), 6-3 margin.

Isner, who had been 0-4 lifetime against del Potro, improved to 16-3 since retiring from Wimbledon in the second round with a left knee injury.

The 28-year-old Isner is 7-8 in title matches, while Nadal is 58-23 in finals. Nadal is 3-0 lifetime against Isner.

The 2013 Cincinnati champ will collect $583,800.