Video: Nadal collapses during press conference

Defending US Open champion Rafael Nadal had a few people worried as he slid from his chair to hide in pain under a conference room table.

The Spaniard was giving his post match responses to the media after beating David Nalbandian 7-6, 6-1, 7-5 in their third round tie on Sunday at Flushing Meadows. During the match the reigning champion looked to be in good form.

He looked to be doing fine in the post match conference as he answered questions in English. However, after feeling a mild cramp in his leg, he only answered further questions in Spanish.

The cramp became all too much for Nadal so he called for his physio to come into the press room, which is practically unheard of. He then slid down his chair like a told-off school child and slipped under the table to hide in his pain.

Nadal lay on the floor for several minutes as the physio worked his magic at the prestigious Flushing Meadows event. After receiving the treatment Nadal stood up and walked slowly out of the pressroom, only to return a few minutes later. He revealed that a cramp to the front and back of his right leg had been the cause of the collapse.

Speaking in Spanish, Nadal said, "It's just bad luck that it happened in public. It was really hot, I ran a lot and you sweat a lot in these conditions."

Nadal is currently enjoying good form and his next match sees a repeat of his third-round clash at Wimbledon this year against Luxembourg's Gilles Muller.