Late call-up Madison Keys put defending champions the United States through to a Fed Cup final against the Czech Republic on Sunday.
Keys was drafted in to replace CoCo Vandeweghe for the fourth rubber against France's Pauline Parmentier after Sloane Stephens thrashed Kristina Mladenovic to put the holders 2-1 up.
And the 23-year-old justified the faith shown in her by US team captain Kathy Rinaldi, defeating Parmentier 7-6 (7-4) 6-4 in Aix-en-Provence to knock the hosts out.
Petra Kvitova got the job done for 10-time champions the Czech Republic in the other semi-final against Germany, seeing off Angelique Kerber 6-2 6-2 to leave the majority of the crowd disappointed in Stuttgart.
Both teams will now prepare for the final, which takes place on the weekend of November 10-11.
IT'S GOING TO BE CRAZY
Keys' selection at the expense of Vandeweghe caused a bit of a stir, but she made sure to leave her mark by defeating France's Parmentier.
It was not all smooth sailing, Parmentier racing ahead in the second set, only to fall short as Keys claimed it 6-4.
"It feels amazing, but not for me - to do that for this team and help us back to the final," Keys told the competition's official website.
"I knew [Pauline] would play well, she was so good against Sloane yesterday.
"I love playing in atmospheres like this, even if they are not all cheering for you it still makes for a great game.
"It is going to be a crazy final!"
SLOANE STARS FOR THE STATES
There was no such danger of Stephens conceding her lead in the earlier rubber, as she made light work of Mladenovic.
It took Stephens just 54 minutes to overcome her opponent 6-2 6-0, and set the stage for Keys' wonderful performance.
CZECHS IN CRUISE CONTROL
It could well have been a hostile atmosphere for the Czech Republic's Kvitova, but the world number 10 held her nerve to ease past Kerber in convincing fashion.
Kvitova and Karolina Pliskova had put the Czechs well in control on day one, and although Julia Georges made it 2-1, Kerber could not complete the comeback for Germany.
In fact, Kerber's hopes were swiftly dashed - Kvitova picking up where she left off on Saturday to send the Czechs through.
PLAY-OFF DELIGHT FOR BELGIUM AND BELARUS
In the World Group play-offs, there were wins for Belarus, Romania, Australia and Belgium.
25. Mai 2018
|Ronaldo: Cristiano and Neymar would be good together at Madrid|
|Rockets honour Santa Fe victims, first responders at game five|
|Real Madrid rejected €150m offers for Asensio – agent|
|Marshall, Baldwin react strongly to Trump´s comments on NFL anthem stance|
|Nabura handed six-week ban for wild kick|
|Pedroia to return for Red Sox on Friday|
|Warriors´ Iguodala ruled out for game five against Rockets|
|Na leads as Spieth makes solid start at Colonial|
|James Harden, LeBron James headline 2017-18 All-NBA first team|
|Manchester United target Fred to decide future after World Cup|
|´Incredible´ Salah is like Messi, says Ronaldo|
|Salah a big candidate for Ballon d´Or - Muller|
|Message from coach keeping Masters champion Reed grounded|
|Anybody can really win it - Seles feels French Open is wide open this year|
|Mambo number 5! - Non-league star channels Lou Bega hit|
|Pakistan to stop wearing smart watches after ICC intervention - Hasan|
|Saha hails ´great man´ Ferguson as legendary Man Utd boss continues recovery|
|Emery´s depth of knowledge impressed Arsenal´s Gazidis|
24. Mai 2018
|Conceicao extends Porto contract|
|Lomax impresses as Saints overrun Tigers|
|McIlroy in contention at Wentworth as Bjerregaard sets the early pace|
|Bad light calls time on Thiem, Wawrinka out in Geneva|
|Garitano in, Canales out at Real Sociedad|
|Caparros accepts new role at Sevilla|
|Pliskova downed by Larsson after drawing Serena in Paris|
|They´re using the anthem as fake patriotism - Warriors coach Kerr critical of NFL|
|Lyon win record fifth Women´s Champions League title|
|French Open 2018: Doing the unthinkable - the men most likely to topple Nadal|
|French Open 2018: How can Rafael Nadal be stopped?|
|Steve Smith named as marquee player for Global T20 Canada|
|Can Emre play? Yes he Can... and so can Milner|
|Liverpool working to help fans after flight cancellations|
|Abbas and Hasan torment sorry England|
|Xavi ´thrilled´ to sign two-year Al Sadd extension|
|Holtby extends Hamburg contract despite relegation|
|Nadal begins French Open defence against Dolgopolov|
|Serena drawn to play Pliskova in French Open first round|
|FA condemns assault of match official|
|Bologna confirm Donadoni departure|
|Yates lead halved in Giro d´Italia|
|Connacht turn to Friend|
|Scotland lose injured Dunbar for June tour|
|Spalletti in ´no rush´ to sign new Inter deal|
|Ricciardo and Red Bull dominate Monaco practice|
|Mauricio Pochettino signs new deal with Tottenham|
|Pochettino signs new deal with Tottenham|
|Istanbul to host 2020 Champions League final|
|Williams sisters given French Open wildcard|
|President Donald Trump praises NFL´s anthem stance|
|Buffon in consideration for Italy call, says Mancini|
|Roberts injured in Broncos win against Eels|
|Atletico complete move for Villarreal star Rodri|
|Ozil, Gundogan not playing politics, says Low|
|Valencia complete permanent Kondogbia signing|
|Fairytale ending could be in the script, says World Cup-bound Vardy|
|Milwaukee police apologise to Bucks´ Brown over tasering|
|Television, crosswords and Nintendo - Koscielny´s remedy to World Cup heartache|
|World Cup not an audition for Barca or Madrid, says Germany star Werner|
|Neck injury rules Kohli out of Surrey stint|
|Nine LaLiga titles and 674 club games under nine managers - Iniesta in Opta numbers|
|49ers Enterprises takes stake in Leeds United|
|Manchester United should sell Pogba if he´s unhappy - Scholes|
|Andres Iniesta´s nine LaLiga triumphs with Barcelona|
|Andres Iniesta: The footballers´ footballer|
|Real Madrid v Liverpool: Salah has foundations in place for Ballon d´Or challenge|
|Iniesta´s Vissel Kobe move confirmed|
|Low upbeat over Neuer´s World Cup hopes|
|´No secrets´ in playoffs, says Celtics rookie Tatum|
|Real Madrid v Liverpool: Salah takes his chances better than Ronaldo - Opta|
|Cubs, Yankees find very different ways to lose|