As Ana returns to the hard courts of the United States this week in quest of success in Los Angeles, not only will she competing in her first tournament since a notable semi-final run at Wimbledon, she will be also be seeking another U.S. Open Series Challenge title.

Now in its fourth season, the U.S. Open Series Challenge provides players an added incentive by offering additional prize money at the U.S. Open based on their performance in the summer swing of Sony Ericsson WTA Tour tournaments in Stanford, San Diego, Los Angeles, Canada and New Haven. Points are awarded throughout the Series according to tournament performances, and the top three finishers are then eligible for bonus prize money at the year’s final Grand Slam.

In 2006, due in large part to Ana’s breakthrough victory over Martina Hingis in the finals of the Rogers Cup in Montreal, Ana edged out Maria Sharapova to finish atop the U.S. Open Series leaderboard.

When you look at the people who have won Montreal or the U.S. Open Series, it was big names. It was pretty amazing that I was one of them.

As champion of the Challenge, Ana earned an extra $40,000 in prize money upon advancing to the third round of the U.S. Open. Although this was undoubtedly a healthy and welcomed supplement, Ana was in fact eligible for an astonishing benefit of $1 million, which is the maximum Series’ bonus for winning the U.S. Open.

In 2005, the recently retired Kim Clijsters earned such a bonus by virtue of winning the Challenge and subsequently taking home the U.S. Open crown. The resulting $2.2 million payout represents the largest purse in the history of women’s sports.

While it may not have come on especially with fans in Europe, the North American tennis-watching public has embraced the Series, with ESPN showing the finals of men’s and women’s events back-to-back each weekend. Noticing its success, Tennis Australia introduced the Australian Open Series earlier this year.

In order to contend for the U.S. Open Series title again in 2007, Ana faces an uphill climb as injuries forced her to miss the first two tournaments of the Challenge, thereby nullifying the opportunity to earn points.

Currently Sharapova, fresh off her first tournament victory of the season in San Diego, is the points’ leader (100pts); she is followed by Stanford winner Anna Chakvetedatze in second (95pts) and San Diego finalist Patty Schnyder in third (82pts).