The Czech Republic won their sixth Fed Cup title in eight years after beating the United States 3-0 in Prague, with two critical wins from world doubles No.1 Katerina Siniakova.
Siniakova saved two match points before defeating Sofia Kenin 7-5 5-7 7-5 to give the Czechs an insurmountable 3-0 lead over the defending champions in the best-of-five final.
It was the first victory for the Czechs over the US - since the country was created after the split of Czechoslovakia in 1993 - after four defeats in the Fed Cup.
The Czechoslovakia team that won five Fed Cup titles was 2-6 against the U.S.
"It was an unbelievable match for me," Siniakova said.
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"It was up and down, with nerves. I'm extremely happy that I won."
In a hard-fought match at the O2 Arena, the 22-year-old Czech saved two match points when Kenin was serving at 5-4, and went on to convert her own second match point on the indoor hardcourt in front of 14,500 fans.
Siniakova wasted a 3-0 lead in the final set and the 19-year-old Kenin, who was playing her second match in her debut Fed Cup tie, fought back.
Kenin, who wasted three break points at 5-5, hit 43 winners but also made 76 unforced errors while Siniakova hit 24 winners.
"It was horrible, the worst (moment)," Siniakova said about the match points she faced.
"But it's not the end until the final match point is converted."
At 3-0 down in the third set, Kenin needed treatment for what seemed to be a thigh muscle problem. The treatment was then repeated several times.
Trailing 3-1, the American wasted five break points in a game that took 19 minutes. But Siniakova hit a forehand winner to break Kenin for the fourth time in the 12th game to take the set.
On Saturday, Barbora Strycova had rallied for a 6-7 (7-5) 6-1 6-4 victory over Kenin to put the Czechs 1-0 ahead and Siniakova doubled the advantage with a 6-3 7-6 (7-2) win over Alison Riske.
