Defending champion Rafal Nadal slipped off his chair in news conference for a painful cramp in his right leg about two hours later after the second seed defeated David Nalbandian in the third round of US Open on Sunday.

Nadal ousted his friend Nalbandian 7-6 (5), 6-1, 7-5 in a match lasting 2 hours, 39 minutes amid a weather of 28 degree and 65% humidity.

In the post-match conference, Nadal suddenly slumped to the floor under a large table off his chair. Media officials cleared the conference room to allow in medical staff and his family.

According to the views on television screens in the working press room,

three people began working on Nadal and after about five minutes he put a leg on the table. Then ice, water and Gatorade were handed to the lying Nadal.

After a few more minutes Nadal sat up and continued with his Spanish-language interview.

Nadal said in a statement he had begun cramping and the pain caused him to slip to the floor.

"I just have cramping in my leg, that's all," Nadal said in his English statement, offering no other details. "There are no questions. I already finished my press conference in English.

"I just have cramping in front and behind (the leg), that's why I was so painful. That's all."

His agent, Benito Perez-Barbadillo, said Nadal told him the pain was so intense that he didn't want to cry and that's why he covered his eyes and went under the table.

According to Perez-Barbadillo, Nadal had drunk two bottles of water and a bottle of Gatorade, also having lunch before he appeared in media conference.