AFP, Paris : Italy kept their Fed Cup title defence on track Sunday, downing the United States to join Australia and Germany in the semi-finals of the women’s tennis competition. Karin Knapp claimed the decisive third point for Italy, giving them an unbeatable 3-0 lead with a 6-3, 7-5 victory over American Alison Riske. The holders won’t know their opponents for the April 19-20 semi- finals until Monday, after rain in Seville forced decisive matches in Spain’s clash with the Czech Republic to be pushed back with the hosts holding a 1-0 lead. Both Italy and the United States were without their top players for the tie on an indoor hard court in Cleveland, Ohio. Italy, seeking a fifth Fed Cup in nine years, were without Sara Errani and Flavia Pennetta, while the United States were without injured stars Serena Williams and Sloane Stephens. But Knapp, ranked 40th in the world, came through with two victories. She opened the tie with a 6-3, 3-6, 6-1 win over Christina McHale on Saturday, when Camila Giorgi crushed US teen Madison Keys 6-2, 6-1. In the meaningless doubles match, Keys and Lauren Davis teamed up to beat Nastassja Burnett and Alice Matteucci 6-2, 6-3 and prevent the whitewash, giving Italy a final 3-1 triumph. US captain Mary Joe Fernandez opted to substitute Riske for Keys in Sunday’s reverse singles, hoping her more aggressive style would prove troublesome for the Italian. Instead, Knapp broke Riske seven times, and while the Italian’s nerves got the better of her in her first two chances to serve for the match, she finished it off in style with a love game punctuated by a service winner on her first match point. “I got a little bit nervous,” Knapp admitted. “I got a little bit of emotion. At the end, the last game, I served again better. I think this was the key.” In Hobart, Australia ensured their place in the next round for the first time in 21 years with a crushing Samantha Stosur- inspired 4-0 defeat of Russia.