Rafael Nadal of Spain serves to Philipp Kohlschreiber of Germany at the US Open tennis championships in New York September 2, 2013.  [Photo/Agencies]

NEW YORK — Rafael Nadal improved to 19-0 on hard courts in 2013 by returning to the US Open quarterfinals.

He will not, however, play Roger Federer next.

The second-seeded Nadal, who counts the 2010 US Open among his 12 Grand Slam titles, came back to beat 22nd-seeded Philipp Kohlschreiber of Germany 6-7 (4), 6-4, 6-3, 6-1 on Monday night in the fourth round.

Their match ended about 2½ hours after Federer was upset in straight sets by 19th-seeded Tommy Robredo, Nadal's quarterfinal opponent. Had Federer won, he and Nadal would have played each other for the 32nd time — and first at Flushing Meadows.

Against Kohlschreiber, Nadal faced only one break point, and saved it. Nadal has yet to lose a service game in the tournament.

Related: Federer knocked out of US Open by Robredo