Brindisi, Italy (SportsNetwork.com) - World No. 1 superstar Serena Williams will be first up for the United States in its Fed Cup semifinal versus host Italy this weekend.

The best-of-five tie will commence when the 19-time Grand Slam champion takes on 36th-ranked Camila Giorgi on Saturday, and that match will be followed by a tilt between 57th-ranked young American Lauren Davis and world No. 15 former French Open champ Sara Errani. The 21-year-old Davis will be making her Fed Cup singles debut.

The reigning Australian and U.S. Open champion and Williams is a perfect 11-0 in her career Fed Cup singles matches.

Sunday's reverse singles have Williams facing Errani and Davis battling Giorgi, while the Day-2 doubles rubber has an American tandem of Christina McHale and Alison Riske meeting an Italian duo of Flavia Pennetta and Karin Knapp on the red clay at Circolo Tennis Brindisi.

Williams' former top-ranked older sister, Venus, decided against playing this week due to personal reasons.

Both the U.S., captained by Mary Joe Fernandez, and Italy, guided by Corrado Barazzutti, are trying to earn a spot in next year's Fed Cup World Group.

The two teams know each other well, having met four times in the last six years, including back-to-back finals in 2009 and 2010. The Italians have won all four of those recent encounters, but team USA leads the all-time head-to- head series, 9-4.

The Americans hold a record 17 Fed Cup titles, but haven't captured the championship now since 2000. The Italians are four-time champs, with all four coming over the last nine years, including as recently as 2013.