Caroline Wozniacki credited her training for next month's New York Marathon as a key factor in her victory over Maria Sharapova in a grueling three-set match in the WTA Finals on Tuesday. Wozniacki won 7-6 (4), 6-7 (5), 6-2 to beat Sharapova for the second-straight time, having also won in the fourth round of the U.S. Open. Tuesday's result in the round-robin match dealt a major blow to Sharapova's hopes of claiming the year-end No. 1 ranking. No such stamina was required in Tuesday's other match as Agnieszka Radwanska had a comfortable 6-2, 6-3 win over Wimbledon champion Petra Kvitova. Read more http://espn.go.com/tennis/story/_/id/11738472/caroline-wozniacki-beats-maria-sharapova-wta-finals