(CNN) -- Three matches and three comfortable wins. Rafael Nadal has made the perfect start to his bid for a record seventh French Open title, but the Spaniard will not face his first serious test until the clay-court grand slam enters its second week.
The two-time defending champion will next play Juan Monaco in the last 16, having crushed one of the Argentine 13th seed's lesser-rated compatriots Eduardo Schwank 6-1 6-3 6-4 in the third round on Saturday.
"I have started well in the tournament -- into the second week now, that is the most important thing," Nadal told reporters.
"Now I have a big confrontation against Monaco. He is having a fantastic season."
Monaco has never gone past round four in a grand slam, but like Nadal he is adept on clay -- having won five ATP Tour titles and reached seven other finals on the dirt surface.
Monaco has won only once in their four meetings, when Nadal retired hurt during a hard-court event in 2007, but he showed his mettle against big-serving Canadian Milos Raonic on Saturday as he came from behind to triumph 6-7 (5-7) 6-3 6-7 (5-7) 6-3 6-4.
Nadal has lost only once at Roland Garros since his first appearance in Paris in 2005, when he began a run of four successive French Open titles, while Monaco's best effort is a fourth-round defeat in 2007.
If he wins, Nadal will then take on his 12th-seeded compatriot Nicolas Almagro or Serbia's world No. 8 Janko Tipsarevic in the quarterfinals.
The 10-time grand slam champion could face a semifinal against world No. 4 Andy Murray, who showed no sign of his worrying back problems on Saturday as he set up a last-16 clash with French 17th seed Richard Gasquet.
"I felt like I moved pretty well today. When you're playing in slams, I just think each day you need to take as it comes. And I felt much better than I did the other day. I felt better than I did yesterday," Murray said after beating Colombia's 50th-ranked Santiago Giraldo 6-3 6-4 6-4.
"So I'm hoping that tomorrow I'll feel good again, and that's all you've got to do is each day just be a little bit better."
Murray had been accused of being a "drama queen" by former tennis star Virginia Wade after receiving lengthy on-court treatment during an earlier match against Jarkko Nieminen, but revealed he had refused pain-killing injections to counter the back pain he has been suffering since the start of this year.
"Guys often during tournaments have numbing shots, if they're just trying to get through a match and are deep in a tournament or whatever," the Scot said.
"But I didn't do that. We got a lot of advice, I saw the doctor here and spoke to him as well, and took all the right medication and did all the right treatments."
Gasquet fought back from a slow start to defeat former world No. 2 Tommy Haas 6-7 (3-7) 6-3 6-0 6-0. The 34-year-old German, now ranked 112th, capitulated as he lost the last 14 games of the match.
"I knew that he had not played long matches in a while. There were quite a lot of people out there, so I really wanted to win this match, to give everything I could," said Gasquet, who lost in the fourth round last year and beat Murray in Rome in April to level their head-to-head record at 3-3.
"It was a beautiful match, and I played really well during the third and fourth sets."
The winner of the Murray-Gasquet match is likely to face world No. 5 David Ferrer in the last eight.
The Spaniard thrashed Russian 27th seed Mikhail Youzhny 6-0 6-2 6-2 to set up a clash with compatriot Marcel Granollers, who beat a tired Paul-Henri Mathieu.
The Frenchman overcame American John Isner in the second-longest match in French Open history in the previous round, which lasted five hours 41 minutes, but he could not repeat the effort as he went down in another five-setter 6-4 6-4 1-6 4-6 6-1.