WASHINGTON -- Venus Williams lost an Olympic tuneup Monday during a World Team Tennis match attended by first lady Michele Obama.

Williams, playing for the Washington Kastles, lost 5-0 to the Boston Lobsters' Irina Falconi in the women's singles portion of the match. In the best-of-five games format, Williams – ranked No. 68 – struggled with her serve, double-faulting several times to the 85th-ranked Falconi.

Obama and daughters Sasha and Malia, who entered Kastles Stadium to applause, saw Williams help the Kastles to 5-1 mixed doubles and 5-1 women's doubles victories, but left before Williams lost her singles match.

"I think I just cooled down, and I couldn't quite get started back up again," Williams said. "In team tennis, you really have to keep your energy up. You have to manage the stop and go. I didn't manage it that well."

Williams is trying to prepare for those types of challenges at the London Olympics, which begin July 28 for tennis. She called the 2012 Games "the ultimate achievement" for her.

"This Olympics is more exciting for me," she said. "All the other ones, I didn't have to worry whether or not I would make it. I was on top of the rankings. I didn't have any problems. It was, for a lack of a better word, for granted. But this time, I had to fight so hard for it, just to get in contention and come back from so much."

Williams, who won singles gold in 2000, has been trying to mount a career comeback after being diagnosed with an autoimmune disease.

"I've been training to bring home medals for the U.S., and I would love if the medal is gold-colored," she said.

Serena Williams is scheduled play for the Kastles on Sunday.

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  • Thursday, July 12: Martina Hingis

    The world's former No. 1 women's singles player leads the visiting <a href="http://www.nysportimes.com/teams/team.aspx" target="_hplink">New York Sportimes</a> in the Kastles' season opener. The 31-year-old is a <a href="http://www.tennis.com/articles/templates/features.aspx?articleid=17082&zoneid=9" target="_hplink">five-time Grand Slam winner</a>, owning <a href="http://www.wtatennis.com/page/Player/Stats/0,,12781~3491,00.html" target="_hplink">43 singles titles</a> and more than $20 million in prize money.

  • Monday, July 16: Venus Williams

    Coming off a disappointing <a href="http://www.huffingtonpost.com/2012/05/30/venus-williams-french-open-agnieszka-radwanska_n_1556525.html" target="_hplink">2012 French Open</a>, Williams will represent the Kastles against the visiting Boston Lobsters. Her original <a href="http://www.washingtonpost.com/sports/othersports/tennis/venus-williamss-kastles-appearance-moved-up-to-avoid-conflict-with-london-olympics/2012/06/04/gJQAL3J4DV_story.html" target="_hplink">July 24 match</a> was moved up to avoid a possible overlap with the <a href="http://www.huffingtonpost.com/news/2012-summer-olympics" target="_hplink">2012 London Olympics</a>.

  • Wednesday, July 18: Sam Querrey

    One of the world's most ferocious serves will be on display when <a href="http://www.atpworldtour.com/Tennis/Players/Top-Players/Sam-Querrey.aspx" target="_hplink">Sam Querrey</a> and the visiting Sacramento Capitals invade Kastles Stadium at The Wharf. At age 19, Querrey turned heads when he reeled off an ATP record <a href="http://espn.go.com/tennis/blog/_/name/tennis/id/2954887/querrey-comes-aces" target="_hplink">10 consecutive aces</a> in a 2007 match against James Blake.

  • Friday, July 20: Chris Evert Fan Reception

    Before the Kastles square off against the Orange County Breakers, <a href="http://www.washingtonkastles.com/teams/article.aspx?article_id=3131" target="_hplink">tennis legend Chris Evert</a> (pictured here at 1978 Wimbledon) will host an event for ticketholders. An <a href="http://espn.go.com/tennis/story/_/id/7626203/chris-evert-signs-four-year-deal-call-tennis-espn" target="_hplink">18-time Grand Slam winner</a>, Evert holds the <a href="http://www.wtatennis.com/player/chris-evert_2257889_2188" target="_hplink">highest winning percentage</a> in pro tennis history (.900).

  • Sunday, July 22: Serena Williams

    Williams returns to D.C. for a <a href="http://www.washingtonkastles.com/teams/article.aspx?article_id=3075" target="_hplink">fifth summer run</a> with the Kastles, and will be the marquee name against the Kansas City Explorers. Like her sister Venus, the 13-time Grand Slam winner was upset in the <a href="http://www.huffingtonpost.com/2012/05/29/serena-williams-french-open-virginie-razzano-upset_n_1554088.html" target="_hplink">2012 French Open</a>, falling in the first round.