NEW DELHI: Avenging his defeat to the Russian in the final two years ago, Novak Djokovic defeated Daniil Medvedev in straight sets on Sunday to win his fourth US Open and a record-tying 24th Grand Slam singles championship.The 36-year-old Djokovic defeated his opponent 6-3, 7-6 (7/5), 6-3 to win, tying Margaret Court for the most Grand Slam victories in Open history and becoming the oldest men's champion in New York ever. "I don't know where to start. It obviously means the world to me," said Djokovic, wearing a...