American tennis star Serena Williams completed her climb back to the top of the tennis world at the US Open, ending a five-year hiatus between stints as the world's No 1 player.

It was a double-dip victory for Williams who beat Jelena Jankovic 6-4, 7-5 in the US Open women's singles championship on Sunday to win the title and the battle for the world number one ranking.

Williams spent 57 weeks at number one between July 2002 and August 2003.

Winning her third US Open title has Williams yearning for more Grand Slams and more weeks at No 1.

"It doesn't stop here," Williams said.

"I feel like I have a new career, like I feel so young and I feel so energised to play every week and to play every tournament. I feel like there's just so much that I can do in my career and I've never felt like I've played my best tennis,” she added.

The 26-year-old American now hopes to join the select group of players who have won 10 or more career Grand Slam titles.

"This is cool because I am at number nine," Williams said.

"I'm pushing the doors closer to double digits which are obviously what I want to get to,” she added.

With three single's title and no majors, Williams needed to win a Grand Slam to validate her season. She lost in the Wimbledon final to sister Venus.