Serena Williams of the United States returns a shot against Caroline Wozniacki of Denmark during their women's singles final match at the 2014 U.S. Open in New York, the United States, Sept. 7, 2014. Williams won match 2-0 and claimed the title. (Xinhua/Yin Bogu)

NEW YORK, Sept. 7 (Xinhua) -- World No. 1 Serena Williams won her third straight U.S. Open title after beating Caroline Wozniacki of Denmark 6-3, 6-3 on Sunday.

It is Serena's sixth U.S. Open title and her 18th Grand Slam trophy. With the win, Serena Williams also becomes the first player since 1978 to win three straight U.S. Open women's singles titles.