World number five Nadal, on Thursday, saw off Youzhny 6-2, 6-3 and will next face either Tommy Haas of Germany or Spanish compatriot David Ferrer.
In the women's tournament, Serena Williams and Maria Sharapova, the top two seeds, also cruised into the quarterfinals.
World number five Nadal looked in fine form early on as he broke Youzhny's serve to move ahead 2-1 and then sealed a double break at 5-2 with a lovely drop shot.
Nadal then served out to take the first set, but after again securing an early break in the second he was pegged back as his own serve was broken for the only time in the match as Youzhny levelled at 3-3.
However, the Spaniard bounced back straight away to break again for 4-3 before sealing the match with a typical backhand crosscourt winner on the run.
The 26-year-old Nadal now stands at 28-2 on the season as he looks to reach his seventh final in seven tournaments since his comeback from a seven-month injury lay-off in February.
Sixth seed Tomas Berdych also progressed into the quarterfinals as he won the battle of the big servers against Kevin Anderson 7-6 (7/5), 7-5.
William dismantled Kirilenko
On the women's side, world number one Williams eased into the last eight as she dismantled 13th seed Maria Kirilenko 6-3, 6-1 in just an hour and four minutes.
Williams didn't even face a break point during the match as she steamrollered the Russian, and she believed taking some pace off her serve to get a higher percentage of first serves into court helped her relax and play more fluently than in her earlier rounds.
"I've just been missing a little bit of my serve when I was hitting it harder, so I took some pace off and just didn't hit it as hard as I usually do," said the American.
"It was better today. I just felt really relaxed. I felt like I was just taking my time so hopefully I can keep calm and relaxed."
Williams is unbeaten on clay in eight matches so far this season, but after a similarly positive start to last season on the clay was followed by shocking loss in the first round of the French Open, she said she has learned not to get overconfident ahead of Paris, where she will head at the end of this month.
"I think more than anything I learned not to become overconfident. I think I'll just take that with me to the French this year. I think I was a little confident last year and I felt really good; this year I'm going to take every moment like it's my last."
'I'm not comfortable on the surface'
World number two Sharapova, who has yet to drop a set, continued her stroll into the quarterfinals as she overcame Sabine Lisicki 6-2, 7-5.
The Russian, who could overtake Williams at the top of the rankings should she win the title, broke the German's serve four times to prevail in a disjointed opening set.
Serve was more dominant in the second set with both players exchanging just the one break early on before Sharapova secured a crucial second break at 5-5 and served it out to take her place in the last eight.
And the reigning French Open champion said she feels more comfortable than she ever has on the clay.
"I think when you win a Grand Slam on a surface, it would be pretty mean of me to say that I'm not comfortable on the surface," she said.
"It took me many years to get to the level of where I am today. It certainly didn't happen overnight.
"I worked extremely hard on getting stronger and recovering better, moving better on the court, giving myself a better position on the court, especially after being on the defensive and trying to play aggressively as I always do on quicker surfaces." – AFP