NEW YORK -- There will be no US Open matchup between Roger Federer and Rafael Nadal this year.

Federer's 18-match Grand Slam winning streak ended with a 7-5, 3-6, 7-6 (8), 6-4 quarterfinal loss to Juan Martin del Potro.

The result prevented Federer and Nadal from meeting in the semifinals, which would have been their first head-to-head showdown at Flushing Meadows.

It's the only major tournament where the longtime rivals have never faced each other.

Instead, it will be 2009 champion del Potro against two-time winner Nadal in Friday's semifinals.

The other semifinal is Pablo Carreno Busta against Kevin Anderson. (AP)