Top seed Rafael Nadal booked his place in the US Open quarter-finals with a business-like victory over fellow Spaniard Feliciano Lopez at Flushing Meadows.
Nadal broke Lopez, ranked 23rd for the tournament, once in each of the three sets to record a 6-3 6-4 6-4 victory that showed him at his most professional rather than dominant.
The 24-year-old was quickly into his stride, breaking at the first attempt as he notched the first three games of the match.
Lopez did manage to halt the procession but Nadal was looking strong and even managed to defend four break points on his way to a 6-3 first-set win.
The Wimbledon champion was forced to work hard at the start of the second set, which followed serve for four games until Lopez capitulated with a weak third service game.
That offered Nadal a chance to seal the set provided he could defend his own serve and with Lopez looking functional rather than inspired he did so, serving to love to clinch a 2-0 advantage.
Lopez continued to work hard but he simply did not have the firepower to dent his illustrious countryman's serve.
Nadal made his move in the ninth game of the third set, breaking and then serving out the match in style.
The world number one will meet Fernando Verdasco in the last eight after he came back from two sets down in another all-Spanish match-up against David Ferrer.
Ferrer, seeded 10th, was the unlucky loser as he went down 7-5 7-6 (10/8) 3-6 3-6 6-7 (4/7).
Eighth seed Verdasco looked down and out after two hard-fought defeats in as many sets but grew as the game went on and played some thrilling shots in a decisive fifth-set tie-break.
Elsewhere, Stanislas Wawrinka followed up his win over Andy Murray by prevailing in a five-set epic against Sam Querrey to reach the last eight of a grand slam for the first time.
The Swiss 25th seed triumphed 7-6 (11-9) 6-7 (5-7) 7-5 4-6 6-4 in a match lasting just shy of four and a half hours to seal a quarter-final tie with Mikhail Youzhny, who saw off the challenge of Tommy Robredo earlier in the day.
Wawrinka said: "It's the first time for me, so for sure I am very happy with that. It's something very important, and I knew before the match it was going to be tough, but I was really focused on the match, on staying with him."
Twelfth seed Youzhny had earlier secured a 7-5 6-2 4-6 6-4 win over Spain's Robredo.
The Russian, a semi-finalist at Flushing Meadows in 2006, was slow out of the blocks but Robredo failed to capitalise.
A single break opportunity in the 11th game saw Youzhny take the lead 1-0. He doubled his advantage with a more measured second set that left Robredo banging his racquet off the ground.
Robredo recovered his composure to take the third set but his hopes were quickly ended as Youzhny broke in the fifth game of the fourth set and held on for the win.
Speaking after his victory, Youzhny said: "I actually liked how I played today.
"Of course, I made some mistakes. I was a little bit lucky in the fourth set but I also missed some chances in the third set.
"I have now reached two quarter-finals in the year (after the French Open) and maybe it will mean I will start to play a little bit more consistently, not just really well in some matches and not in others.''