Wimbledon champion Petra Kvitova returned to action with two wins as she guided the Czech Republic to their fourth Fed Cup final in five years.
Kvitova followed up Saturday's win over Kristina Mladenovic with a 6-4 6-4 victory against Caroline Garcia to put the champions 3-0 up on France.
The world number four had citing exhaustion.
Russia will provide the opposition in November's final following a 3-2 win over Germany in Sochi.
In Poland, Martina Hingis missed out on a first singles win since 2007 as she lost 4-6 7-5 6-1 to Urszula Radwanska.
The 34-year-old Swiss, a five-time Grand Slam champion who made her Fed Cup debut 20 years ago, led 6-4 5-2 but took just one of the next 12 games.
Hingis had in Saturday's opening singles rubber, but Switzerland won the doubles to take the tie 3-2.
Also in the World Group play-offs, world number one Serena Williams could not prevent a 3-2 defeat for the United States against Italy in Brindisi.
Williams managed two singles victories but could not claim the decisive third point as - playing doubles with someone other than her sister Venus for the first time since 2002 - she and Alison Riske lost 6-0 6-3 to Sara Errani and Flavia Pennetta.
"Today has been a big eye opener," Williams said of playing on clay.
"I need to go home and really train. I'm totally not as ready for clay-court season as I thought I was. Next time I'll be really, really ready and I'll know what to expect.
"Now I'm in the mindset of, 'You know what, I'm not on hard court.' I'm playing like I'm on hard court and I'm not. So I have to play and be ready to hit a thousand shots if necessary."
In Ostrava, Kvitova was back on court after a self-imposed six-week break from tennis as she admitted she had lost her motivation for a time.
She had too much for world number 29 Garcia, however, taking the Czechs to within sight of adding another title to those won in 2011, 2012 and 2014.
"Petra did a great job," said Czech captain Petr Pala. "She must have been terribly nervous on Saturday because her break was quite long, but she handled it like a great player."
Russia, without the injured Maria Sharapova, edged past last year's finalists Germany, thanks to a 6-2 6-3 doubles victory for Elena Vesnina and Vera Zvonareva over Angelique Kerber and Andrea Petkovic.