SURPRISE, Ariz. — A fiesty teenager and a transplanted South African led the way in a comeback victory for the United States over Argentina on Sunday in the first round of the Fed Cup.

Melanie Oudin, a 17-year-old from Marietta, Ga., kept the United States alive by rallying to beat Betina Jozami 2-6, 6-1, 6-2 and tie the best-of-five competition at 2-2.

Then Liezel Huber, born in South Africa but a U.S. citizen since July 2007, teamed with Julie Ditty to beat Jozami and Gisela Dulko 6-2, 6-3 to give the United States the victory 3-2.

"We wanted it to come down to the doubles," U.S. team captain Mary Joe Fernandez said. "When Liezel's on the court I feel really confident every single time."

Huber and her usual partner — Cara Black of Zimbabwe — are the No. 1 ranked doubles team in the world. After the match, Huber took the American flag and paraded it around the court.

"Everybody got to play and everybody gave it their all," Huber said. "It's a proud day in my history book."

Fernandez decided at the last minute to go with the left-handed Ditty rather than Oudin or Jill Craybas. Ditty joined the team only after Bethanie Matteck withdrew on Tuesday because of a nagging hip injury.

"I just did what Liezel told me to do," Ditty said with a laugh.

The triumph at the Surprise Tennis and Racquet Complex in chilly suburban Phoenix sends the United States into a semifinal matchup against the Czech Republic. Defending champion Russia will face Italy in the other semifinal.

Argentina had taken a 2-1 lead in Sunday's' first match when Dulko defeated Craybas 6-1, 6-3 in a meeting of the top two players in the competition.

That left everything on the shoulders of Oudin, who turned pro only last year and is ranked 151st in the world.

"She really dug deep," Fernandez said. "For someone so young playing in their first Fed Cup when it's all on the line there — she had to win to stay in it — she really came through."

Oudin acknowledged that she felt the pressure of having the team's fate left up to her.

"I think that going into the match I was thinking about it a little bit too much and that's why I don't think I started off too well," she said. "But after the first set, I mean I knew I could beat her and I knew I could play better than that."

Oudin's victory was interrupted by a 30-minute rain delay. She was up 4-0 in the second set when the delay came.

When play resumed, the second set ended with a double-fault by the 20-year-old Jozami.

Oudin lost the first two games of the last set, then dominated the next six. Through it all, she kept her and the bundled-up pro-USA crowd's attention by yelling to herself after virtually every shot.

"One of my huge things is my mentality on the court," Oudin said. "I never think that any point is different, even if I'm down like 5-0, I'm going to be running down every single ball and fighting as hard as I can."

Two of the games ended when Jozami, ranked 134th in the world, couldn't finish off with her trademark drop shots at the net.

"She was obviously better than me," Jozami said before quickly returning to the court for the deciding doubles match. "I don't know how to explain it. I couldn't come back like happened in the first set."

The United States has won 17 Fed Cup titles but none since 2000. Argentina has never won a Fed Cup but has been to the semifinals twice.

Fernandez invited Serena and Venus Williams to participate but the sisters declined, citing scheduling difficulties. The semifinals will be played, probably on clay, April 25-26 in the Czech Republic.

"I'm hoping Venus and Serena will be available and they can play," Fernandez said. "You always want the very, very best and Serena and Venus are the very, very best. But you go with who can play and who's ready to go, and my team was ready to go."