NEW YORK: American Serena Williams defeated second seed Jelena Jankovic 6-4, 7-5 in the women's US Open final Sunday for her ninth career Grand Slam title and the world No 1 ranking.

There was plenty at stake as fourth-seeded Williams received the WTA top ranking, a spot she previously held for 57 weeks beginning in 2002.

"I am so excited," Williams said. "I wasn't even going for number one. It is just an added bonus."