Andy Murray, considered by many to be a favorite to win the U.S. Open, put in a lackluster performance Tuesday and lost to Marin Cilic of Croatia 7-5, 6-2, 6-2. By the second set, Murray was wincing when moving his left wrist, though he said that was no excuse for the loss, adding that he hopes to to win the Australian Open next year. Meanwhile, Serena Williams defeated Flavia Pennetta handily, 6-4, 6-3. Tomorrow's marquee match features 17-year-old Melanie Oudin in her first pro tennis quarterfinal. As this is being written, Rafael Nadal and Gael Monfils are engaged in an all-out slugfest with one set apiece.