Nadal, 25, was talking to journalists two hours after his third round win over close friend David Nalbandian, when he grimaced in pain, screwed up his eyes and slumped in the back of his chair, feeling his right leg.
The world number two, a winner of 10 Grand Slam titles, slipped to the floor behind the table where he had been sitting, and out of view of the media, while tournament medical staff were summoned.
Scores of reporters and camera crews were ushered out of the interview room deep inside the Arthur Ashe Stadium, but the drama was still relayed into the nearby media centre by the internal television feed.
The conference room lights were switched off before the top of Nadal's right leg was suddenly silhouetted above the desk as the physios got to work.
After 15 minutes of treatment, Nadal was back on his feet, insisting that the problem was merely cramping.
"It was just cramping in the right leg, in the front and in the back. It was very painful, that's all," said Nadal, who resumed his news conference standing instead of sitting.
A smiling Nadal said the incident will not affect his preparations for his fourth round match against Luxembourg's Gilles Muller, scheduled for Tuesday.
"I will train normally on Monday. It was just a normal cramp that could have happened anywhere, but it's just bad luck that it happened in the press room. Anywhere else, nobody would have noticed." (AFP)
