James Waterson reports on the day's tennis news. Caroline Wozniacki and Maria Sharapova lead their respective groups at the WTA's year-end championships, and there are some interesting match-ups in store. Janko Tipsarevic beat Viktor Troicki in the ATP's first all-Serbian final in Moscow, and the win moved him up to No. 10 in the race for the ATP World Tour Finals. The WTA announced player participation increased 24 percent while withdrawal rates decreased 18 percent.