CLEVELAND -- Karin Knapp won her second match of the weekend and gave Italy a 3-1 win over the United States in their Fed Cup first-round match on Sunday.
Knapp defeated American Alison Riske 6-3, 7-5 to give Italy the victory in the best-of-five series.
She held a 5-2 lead in the second set, only to let Riske tie it at five. But Knapp regained the momentum and closed out the match.
"I got a little bit nervous, I got a little bit of emotion," Knapp said. "But I tried to continue my game, to hit the ball hard, to command the game."
Knapp also defeated Christina McHale on Saturday, 6-3, 3-6, 6-1. Camila Giorgi defeated Madison Keys 6-2, 6-1 in Saturday's second match.
U.S. captain Mary Joe Fernandez chose the 46th-ranked Riske over Keys, who is the team's top-ranked player at No. 37 in the world, as Knapp's opponent.
Riske fought hard through the second set and appeared to gain control before Knapp shut the door.
"I had to do something differently because she was completely attacking me. I tried to be the first one to go after it," Riske said. "She was serving really well today."
Lauren Davis and Madison Keys of the United States earned a 6-2, 6-3 win in the doubles match against Nastassja Burnett and Alice Matteucci.
Italy moves on to the World Group semifinals April 19-20 to face either Spain or the Czech Republic, whose first-round tie has been extended into Monday because of rain.
"I said this morning, `If we win we have to jump into the snow."' Knapp said. "So after, we will all put the jacket on, the scarf on and we will jump in the snow."
The United States moves to the World Group Playoff in April and will need to win in order to stay in the World Group. The U.S. Fed Cup team is 0-11 after trailing 0-2 after the first day of play since the World Group format began in 1995.