Rafael Nadal of Spain returns a volley to compatriot Tommy Robredo during their men's quarterfinal match at the US Open tennis championships in New York, Sept 4, 2013. [Photo/Agencies]

On the men's side second seed Rafa Nadal continued his remarkable 2013 form, improving his hardcourt record to 20-0 with a 6-0 6-2 6-2 hammering of fellow Spaniard Tommy Robredo.

Next up for Nadal is France's Richard Gasquet, who will be playing in the semifinal stage of a Slam for the first time since Wimbledon in 2007.

Robredo had spoiled what would have been the first meeting at the US Open between Nadal and all-time Grand Slam king Roger Federer after the 31-year-old Spaniard sent the Swiss master packing in straight sets in the fourth round.

Nadal, who has come back from knee injuries that sidelined him for seven months to win nine tournaments including his eighth French Open for his 12th Grand Slam crown, bounded for joy after steamrolling another opponent at Arthur Ashe Stadium.

"I think I played my best match in the US Open this year," said 2010 US Open winner Nadal, who has lost just one set from five matches. "Playing a little bit better every day is great."