Novak Djokovic cruised past Spain's Pablo Carreno Busta 6-0, 6-1 to join Rafael Nadal, who racked up his 300th career clay court win, and Roger Federer, who saw off Lukas Rosol, in the quarterfinal of the Monte Carlo Masters.
World number one Nadal finished with an ace on match point to seal his landmark 6-1, 6-3 win over Italy's Andreas Seppi while and Federer saw off Czech Lukas Rosol.
Nadal became just the 11th man to crack 300 wins on clay -- the last to do so was Spaniard Carlos Moya, who ended his career in 2007 with 337 victories.
Nadal still has ground to cover on clay before approaching the all-time top winner on the surface -- Argentine Guillermo Vilas who compiled a record of 644-183 on the surface three decades ago.
The Spaniard said he felt an improvement in his play against Seppi, with the win taking him into another meeting with compatriot David Ferrer.
Spanish sixth seed Ferrer booked his place by beating Bulgarian number 12 Grigor Dimitrov 6-4, 6-2.
"I did what I had to," said top seed Nadal. "But playing David (Ferrer) is never easy. If you are not at the top of your game you will lose. I'm just glad to be in a quarter-final."
Nadal had a few spots of bother against Italy's Seppi, with the world number one forced to save five break points in the sixth game of the opening set for a 5-1 lead.
"At 4-1 I just stopped moving my legs, it was mental, not physical," he explained.
- 'Quarter-final will take longer' -
In the second set, Nadal dropped serve to love while leading 4-2. But he got it straight back for 5-3 and finished off the victory in 93 minutes.
Djokovic, who ended Nadal's eight-year Monte Carlo winning run in 2013, put in what amounted to a training session as he won the first nine games in a 6-0, 6-1 rout of lucky loser Carreno Busta which took 47 minutes.
"My object is to keep playing like this," said the Serb. "It's impossible to predict the future, but I'm sure my quarter-final will take longer than this match.
"I'm inspired to be defending this title and want to keep playing at my top level."
Djokovic next plays Spanird Guillermo Garcia-Lopez, who beat fifth seed Tomas Berdych 4-6, 6-3, 6-1 with the Czech reportedly suffering with a back injury.
Third seed Stanislas Wawrinka earned a free trip into the last eight when Spain's Nicolas Almagro retired before their third-round match with a foot injury.
The Australian Open winner will face Canadian eighth seed Milos Raonic, who beat 11th-seeded Spaniard Tommy Robredo 6-4, 6-3.
Seven-time Wimbledon champion Roger Federer, the fourth seed, spent just 57 minutes on court getting past Rosol 6-4, 6-1 and next plays ninth seed Jo-Wilfried Tsonga.
Federer, the record 17-time Grand Slam winner, came back from a break down in the first set before crushing his opponent to win an ATP-leading 26th match this season. He won 10 of the last 11 games.
"I was able to find my way into the match," said the Swiss, 32.
"After four games you usually know what's going to work, what's not going to work.
"I also came to the net some, I was effective on break points. My first serve started to work better. It was a more difficult start to the match. But as long as I found a way to turn it around and stay calm, it was good, I was very pleased."
Frenchman Tsonga celebrated his 29th birthday with a win in controversial circumstances over flamboyant Italian Fabio Fognini, who went into meltdown in a 5-7, 6-3, 6-0 defeat.
The 10th seed won just four points in the final set, where he was jeered by fans.
"Today I felt a lot better than the first day, where my legs felt very heavy," said Tsonga. "I knew I could stay on the court for a long time.
"In the beginning he was better than I was physically, but I made him play each point and I didn't make any unforced errors."