Katerina Siniakova beat Sofia Kenin in a marathon three-set battle on Sunday to lead the Czech Republic to a sixth Fed Cup title in eight years after defeating the United States in the final.
Siniakova, the world number 31, snuffed out two match points to beat the 19-year-old, 52nd-ranked Kenin 7-5, 5-7, 7-5 in three hours and 45 minutes to wrap up a 3-0 victory.
It is an 11th overall title for the Czechs, five of which came as the former Czechoslovakia, a haul second only to the US and their record of 18.
"It was an incredible game for me, up and down, lots of nerves," Siniakova said. "I'm just terribly happy I've won."
"I was so nervous I can't describe it and I'm really looking forward to some time off," she added.
Groundstrokes and long rallies prevailed in Sunday's rubber as both Siniakova and Kenin struggled with their serves, losing it more often than not in the first set.
But the 22-year-old Czech, who is the world number one for doubles alongside her teammate and compatriot Barbora Krejcikova, managed an extra break to take the set 7-5 as Kenin made 23 unforced errors.
The Russian-born American making her Fed Cup debut kept piling up errors early into the second set with Siniakova taking a 3-0 lead.
The American number one for the tie despite still seeking her maiden WTA singles title, Kenin regained composure in time to win the next four games before taking the set 7-5 as Siniakova visibly struggled with her nerves.
The Czech took another 3-0 lead in the third set and held on to the advantage in an interminable 19-minute game five.
But Kenin, who underwent treatment on her left thigh, came back and took a 5-4 lead before earning two match points.
"I felt terrible there. The worst," said Siniakova.
"But you keep playing until the last match point is won."
That is what happened -- Siniakova took the game, earned a break and won the set 7-5.
On Saturday, Barbora Strycova, the world number 33, came from a set down against Kenin to win 6-7 (5/7), 6-1, 6-4 in the Czech's last Fed Cup rubber before retirement.
Siniakova then saw off 63rd-ranked Alison Riske 6-3, 7-6 (7/2).
The US, whose head-to-head record against the Czechs is now 10-3, were missing Sloane Stephens, Serena Williams, Venus Williams and Madison Keys.
The Czechs were without Karolina Pliskova and two-time Wimbledon champion Petra Kvitova, who missed the final with a bad cold.