(CNN) -- Rafael Nadal and Novak Djokovic remain on course for a final showdown at the Shanghai Masters as both cruised into the quarterfinals with convincing victories in China on Thursday.
Rafael Nadal proved too strong for his compatriot Tommy Robredo in the Chinese event.
World No. 2 Nadal, top seed in the absence of the resting Roger Federer, crushed fellow Spaniard Tommy Robredo 6-1 6-4 to set up a clash with Ivan Ljubicic on Friday.
Ljubicic progressed when French 11th seed Gael Monfils retired with a back problem while trailing the unseeded Croatian 6-2 3-0.
Nadal romped through the first set but went 2-0 down in the second before quickly breaking back, then leveling at 4-4.
He broke Robredo to love in the ninth game and then went 40-0 up on his own serve before his 14th-seeded opponent saved a match-point.
Nadal then faulted with his next serve, but his wickedly-spinning second attempt forced Robredo to hit his return high and wide.
Second seed Djokovic similarly dispatched German qualifier Rainer Schuettler, winning 6-4 6-2, and will next face eighth seed Gilles Simon.
"I didn't play the last couple of games of the first set that well, but the important thing is that I played as much as I needed, to win," the Serbian told the ATP Tour's official Web site.
"I've been working on physical strength and fitness a lot in last couple of months, and it's been paying off. When you are playing week after week, it's important to be physically strong, and that gives you advantage over your opponents.
"[Simon] is one of those tricky players on the tour who you don't want to really play. And it's not fun to play him, because he gets a lot of balls back, and he moves very lightly on the court. I'm well aware that's going to be a long match."
Frenchman Simon defeated unseeded Czech Tomas Berdych 6-3 6-4 to keep up his bid to claim one of the three remaining ATP World Tour Finals places.
Sixth seed Nikolay Daydenko is also on track for a spot at the eight-man season-ending event in London after beating fellow contender Fernando Gonzalez 6-3 7-5.
The Russian needed just 82 minutes to defeat the 10th-seeded Chilean and set up a quarterfinal clash with Radek Stepanek on Friday.
The Czech 13th seed progressed when unseeded Swiss Stanislas Wawrinka retired with an abdominal injury, with Stepanek leading 3-6 7-6 (7-5) 4-2 in a match that had already lasted two hours and 22 minutes.
French Open finalist Robin Soderling moved into eighth place in the ATP Tour standings as he beat fifth seed Jo-Wilfried Tsonga of France 6-3 6-3 to reach the quarterfinals.
The ninth-seeded Swede went ahead of Gonzalez in the race for a place in London next month as he won 74 percent of points on his serve.
The 25-year-old will next play Spain's Feliciano Lopez, who beat Austrian Jurgen Melzer 5-7 7-6 (7-3) 6-1 in a battle of two unseeded players.