Champion Serena says she just getting started again

NEW YORK (Reuters) - Serena Williams worked long and hard to reign once more as U.S. Open champion and world number one, and after achieving both goals on Sunday said she felt like she was just getting started again.

"I feel like I have a new career, like I feel so young and I feel so energized to play every week and to play every tournament," the 26-year-old American said after beating Jelena Jankovic 6-4 7-5 for her third U.S. Open title.

"I feel like there's just so much that I can do in my career yet, and I've never felt like I've played my best tennis."

The triumph gave her a ninth grand slam title and first U.S. crown since 2002. It also propelled her to the world number one ranking for the first time in five years.

The powerful Williams said a rededication to fitness and getting into top tennis shape had put her back on the road to success after years in which injuries and off-court interests combined to hold her tennis game back.

"I've been working so hard all year. Sometimes I wake up at like six in the morning to go practice and it was too dark, I would have to wait until it gets light," she told reporters. "It's just paying off.

"No one really, really knows the work that an athlete puts in. You know, it's worth it. Then I felt like, 'Gosh, I've been working the hardest. I should win'."

Williams has been moving back up the rankings as her form improved and she entered more events.

"I've been playing a lot, even last year, and I worked my way back into the top five very briefly. Then unfortunately I lost that, but I was always in the top 10," said Williams, who won the 2007 Australian Open title ranked 81st in the world.

"This year I started out again top 10 and was working my way up, so it's just been consistent. It hasn't happened all of a sudden."

She said she was not satisfied to stop at nine grand slam singles titles.

"I want to get double digits. I like that I'm at nine because I'm pushing for 10, and I feel like I can do it.

"I obviously play well all the time in Australia, so that's coming up soon," said Williams, winner of three Australian crowns.

"I have to win another French Open," said the 2002 Roland Garros winner. "And I love Wimbledon. I definitely have the game to do it.

"I love winning grand slams, so I look forward to it."

Asked for one word to describe Sunday's triumph at the scene of her first grand slam victory nine years ago, Williams said, "Magical."

"Because it was," she explained. "It was just magical. It was everything coming together, like magic.

"And it doesn't stop here."

(Editing by Pritha Sarkar)