|Rafael Nadal of Spain reacts after his match against David Nalbandian of Argentina during the U.S. Open tennis tournament in New York, Sunday, Sept. 4, 2011.|
8. Federer-Nadal: With the Roger Federer-Rafael Nadal dominance of 2005-10 showing no signs of abating when the year began, most thought that Federer would slowly fade and usher in an era of Nadal dominance.
However, Novak Djokovic spoilt the party. He captured the No. 1 crown in July and shows no signs of relenting. (November-end Nadal had 9575 ATP points to Federer's 8170. And Djokovic? 13675!) Three Grand Slams in a year in the face of Federer-Nadal is truly phenomenal!