Serena targets 18th major

New York - World number one Serena Williams is firing on all cylinders as she seeks to stretch her tally of Grand Slam singles titles to 18 at the US Open.

The familiar hardcourts of Flushing Meadows, where Williams has lifted the trophy the past two years and a total of five times, is just the place to end her 2014 Grand Slam drought.

The American superstar hasn't made it past the fourth round of a major this year.

But she has won two of her five 2014 titles in the buildup to the Open, signalling she won't surrender her crown without a fight.

Her straight-sets win over Ana Ivanovic in the final at Cincinnati showed Williams at her dominant best.

"At some point of the match, I actually felt quite embarrassed walking from one side to the other for returns," Ivanovic said of the near-hopelessness of returning Williams' serve.

It was a long way from Ivanovic's fourth-round victory over Williams at the Australian Open, where the American was hindered by back pain.

Back trouble, and the virus that left her weak and woozy in doubles after her shock third-round singles exit at Wimbledon, are all in the past, Williams said.

"I'm in some of the best shape I've been in," she said. "I can play long points and be ready to go again. I feel really fit -- 32 is the new 22, right?"

An actual 22-year-old, Simona Halep, will be among those trying to topple Williams in New York.

The Romanian has been knocking at the door of a first Grand Slam title this year, finishing runner-up to Maria Sharapova at Roland Garros.

Halep also reached the quarter-finals of the Australian Open and the semi-finals at Wimbledon as she climbed to number two in the world.

Williams will also be challenged by more familiar foes, including Sharapova.

Sharapova's appetite is only greater after she missed last year's US Open with a shoulder injury that brought her season to a premature close.

She sealed yet another return from injury by capturing her fifth career Grand Slam in Paris, but she has never won two majors in the same year.

"I only have one more chance to do that this year," she said, and admitted that such milestones matter.

"At this position, that's where you showcase how strong you are and how much you really love it and (want) to show your legacy through the sport," she said.

Just who else might emerge to challenge Williams is unclear.

Australian Open champion Li Na of China is an injury absentee, while Czech Petra Kvitova has been an early casualty in the two tournaments she has played since winning Wimbledon.

Eugenie Bouchard, who reached the semi-finals at the Australian and French Opens before becoming the first Canadian woman to reach a Grand Slam final at Wimbledon, has failed to impress since her crushing loss to Kvitova at the All England Club.

The Belarusian, owner of two Australian Open titles, has been limited to just six events in 2014.

She battled a foot injury for much of the year and withdrew from her title defence at Cincinnati with a right knee injury.

Russian veteran Svetlana Kuznetsova, who won the US Open in 2004, arrives in New York having snapped a four-year WTA title drought at Washington in August.

Australian Samantha Stosur -- whose 2011 US Open triumph makes her the last woman to beat Williams in a final at Flushing Meadows -- has had a largely forgettable season.

Also among the former champions in the field, Venus Williams has failed to shine in Grand Slams this year, but won her 45th career title at Dubai and reached the final at the US Open tune-up in Montreal - where she fell to Poland's Agnieszka Radwanska.

That Canadian run included a her first victory over younger sister Serena since 2009, adding intrigue to the possibility of a clash between the sisters in New York.

Ivanovic, the 2008 French Open champion, has never been past the US Open quarter-finals. But the former world number one is enjoying a resurgence this season and will be back in the top 10 in the world rankings for the year's last Slam.

"Definitely exciting times," said Ivanovic, who nevertheless knows that the spotlight will be firmly on Williams unless someone can wrest it away.

In her opinion, that's as it should be.

"We are lucky to have someone like her in our game," Ivanovic said.