Rome, Italy (SportsNetwork.com) - Seven-time champion Rafael Nadal secured a berth in the quarterfinals, while third-seeded Andy Murray withdrew from the Italian Open, a clay-court French Open tune-up.

The fourth-seeded former world No. 1 Nadal handled 16th-seeded American John Isner 6-4, 6-4 on Thursday at Foro Italico.

The nine-time French Open champion was last year's Rome runner-up to three- time Rome champ Novak Djokovic. The two great stars have combined to win the last 10 titles at this Masters 1000 tournament.

Nadal will face Swiss slugger Stan Wawrinka in Friday's quarterfinals.

Meanwhile, Murray said he was fatigued after winning each of the last two clay-court events in Munich and Madrid.

"It's been a very long three weeks for me, the longest I've ever had on clay," said Murray, who had never even reached a clay-court final before his triumph in Munich.

Murray followed that with a surprising win in Madrid, beating Nadal in the final.

"The point is I did not expect to do what I have done in the past few weeks," Murray added. "My body has never done that before on clay. My body's always found the surface difficult. I also don't want to risk making it worse. In the past maybe I've done too much."

The French Open is just over a week away, as the year's second Grand Slam starts May 24 in Paris. Murray's best results at Roland Garros were semifinal appearances in 2011 and last year.

"I wanted to play in this tournament, it's a big event with a lot of points on offer," Murray continued. "The time of year is tough for everyone, it's just one of those things."

David Goffin of Belgium earned a spot in the quarterfinals with the walkover against Murray, who's still 10-0 on clay this year.

Also on Day 4, seventh-seeded David Ferrer tackled fellow Spaniard Guillermo Garcia-Lopez 6-1, 6-3 and an eighth-seeded Wawrinka topped Austrian Dominic Thiem 7-6 (7-3), 6-4.