Rafa Nadal edged closer to a place in his first US Open final after thrashing fellow Spaniard Feliciano Lopez 6-3 6-4 6-4 on Tuesday with another devastating serving performance.
The world number one, who would complete the collection of grand slam titles with a victory at Flushing Meadows, shrugged off swirling winds at Arthur Ashe Stadium to wrap up his fourth straight sets win of this year's championship in a little over two hours.
The start was delayed because of a backlog of matches and did not finish until early Wednesday morning despite Nadal's best efforts to get it over as quickly as possible.
The result appeared a foregone conclusion from the moment Nadal strolled out to centre court, dressed menacingly in an all-black outfit, and opened up a 3-0 lead.
"I think I am playing well, but I am not playing yet at my highest level," Nadal said.
"I am playing better and better every day and I had to play a little bit better this match."
Nadal has yet to lose a game on his service in the entire championship and against Lopez, the 23rd seed, he won a staggering 90 per cent of first serve points. His fastest delivery was timed at 135 mph (217 kph).
Lopez had a great chance to break Nadal in the first set when he had him 0-40 but the top seed immediately snuffed him out.
"I didn't play bad but he played better in (the) important points than me," Lopez said. "Rafa, he doesn't give you so many chances in one match."
Nadal has worked hard on his serve in the belief that it is key to his chances of finally conquering New York. If his form over the past week is any guide, the wait may soon be over.
"To be in quarter-finals of the U.S. Open without losing a set and without losing a serve, two things must work really well: the concentration and the serve," Nadal said.
Nadal's opponent in Thursday's quarter-final is another Davis Cup team mate, Fernando Verdasco, who advanced the hard way by wearing down David Ferrer 5-7 6-7 6-3 6-3 7-6 after almost four and a half hours on court.
"Yeah, that was long, but I played in Australia five hours 15 minutes in semi-finals, and I had to play the final one day later," Nadal said.
"I was very tired, but I was ready. I think for sure he's gonna be ready."