Defending champion Andy Roddick coolly demolished Spain's Tommy Robredo 6-3 6-2 6-4 to book his place in the quarter-finals of the US Open.
The American second seed took just 23 minutes to wrap up the opening set with his energetic play in New York.
Roddick produced a faultless display of his trademark thundering serves to cruise to the second set.
Robredo glimpsed his first break points in the third set but he could not take them and Roddick rolled on to victory.
"I thought I played pretty well," said Roddick.
"I'm serving well, I'm breaking (serve) a lot. I'm returning
well and moving well.
"I think I'm up to 50% for breaking
this tournament, which is extremely high for me."
The 22-year-old American will now meet rising star Joachim Johansson for a place in the last four.
The Swede swept aside France's Michael Llodra 6-2 6-3 6-2 to advance to the quarter-finals.
The big-serving left-hander comfortably took the first set as Llodra struggled to cope with his powerful volleys.
Johansson dropped his second service game of the tournament in the second set but that was all he conceded.
The 28th seed, who increased his ace tally to a total of 76 at Flushing Meadows, is enjoying his best performance in any Grand Slam.
Roddick added: "That's going to be very different from my four matches so
far, there's going to be a lot of serving and I don't know how
much of the time is going to be spent trading groundstrokes.
"I've played pretty well so far but it's a clean slate at
the start of every match."