@engineer,
Excerpted from site at link:
"WIMBLEDON, England -- First Rafael Nadal took a tumble into the net. Then he began complaining to the umpire. Then he bumped his opponent, Lukas Rosol, during a changeover.
Rosol thought the contact was intentional."...
..."Nadal's demeanor grew glum as the match progressed, and in the third set, he bumped into Rosol as they crossed to reach their chairs for a break.
"He wanted to take my concentration," Rosol said. "That's OK. I knew he would try something, but I was concentrating."..."
..."Following the match, Nadal declined to say what had him annoyed.
"Anything that I will say now will sound against me," he said. "It's not the right moment for me to say what happened out there, because it's going to sound like an excuse."..."
http://www.huffingtonpost.com/2012/06/28/rafael-nadal-upset-lukas-rosol-wimbledon_n_1635606.html