Both matches featured familiar US Open rivalries: The first match of the day was No. 1 seed Novak Djokovic against No. 3 Roger Federer. The two were facing off on Finals Weekend for the fifth straight year and in the semifinals for the fourth straight year, including a classic matchup from 2010 in which Djokovic erased two match points with forehand winners to upend the five-time champion.
The second match was a rerun of the 2008 semifinal between No. 2 Rafael Nadal and No. 4 Andy Murray. The Scotsman won that encounter but entered the 2011 semifinal as a decided underdog to the reigning US Open champion, who had lost just one set in his previous 12 matches in Flushing Meadows.


