American Serena Williams defeated second seeded Jelena Jankovic 6-4, 7-5 in the women's US Open final for her ninth career Grand Slam title and the world number one 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 was not even going for number one. It is just an added bonus," she said.

Williams, playing in her first US Open final in six years on Sunday, also picked up $1.5 million in first-place prize money and moved into third on the all-time money list.

The 26-year-old Williams won her 32nd career singles title and wiped away some of the disappointment of losing to sister Venus in the Wimbledon final in 2008.

Williams fired three aces and hammered 44 winners in the two hour, four minute match in front of a crowd of 19,000 at Arthur Ashe Stadium.

Williams, who also won the US Open in 1999 and 2002, is enjoying a revival in her game as she stormed through all seven rounds at Flushing Meadows without dropping a set en route to posting her fourth singles title of 2008.

The 21-year-old Jankovic came out with more spark in the opening set, taking an early break to go up 2-1. But Williams broke back in the fourth, sixth and 10th games to take the set.

Williams clinched the match on her second match point, blasting a backhand winner into the open side of the court. She celebrated by throwing her racket into the air and then jumping up and down before going to the net to shake Jankovic's hand.