Aryna Sabalenka's day of wild extremes ended with Belarus clawing their way into the Fed Cup final while Naomi Osaka's participation ended more tamely when she was benched as Japan lost.
Belarus beat the Netherlands 3-2 in the Hague. Russia was also forced to go the distance as they beat Romania 3-2 in Cluj-Napoca.
Spain swept Japan aside 3-1. Switzerland beat Canada, Belgium beat Kazakhstan and Slovakia beat Britain, all 3-1. Germany thrashed Brazil 4-0 in warm conditions in Florianopolis.
They join already-qualified Australia, France, Czech Republic and Hungary in the 12-team finals in Budapest in April.
The final place was to be decided later Saturday in Everett, Washington, where the Serena Williams-led USA, who also boast newly crowned Australian Open champion Sofia Kenin in their team, started the second day leading Latvia 2-0.
In the Hague, Sabalenka opened the day by losing 6-4, 6-4 to Kiki Bertens. It was a match notable for an awful miss by the Belarussian who seemed to start crying after netting an easy winner.
"It was not the best tennis from myself," Sabalenka said.
When Arantza Rus won the opening set of the fourth rubber to love and Aliaksandra Sasnovich took an injury time out in the next rubber in clear distress with a wrist injury, Belarus seemed doomed.
Somehow Sasnovich battled back to win 0-6, 7-5, 6-2.
Then, in front of a noisy home crowd, Sabalenka and Sasnovich teamed up to outlast Bertens and Demi Schuur in a taut doubles to win 6-4, 3-6, 7-6 (10/8).
A nervy deciding set went to a tiebreak, Belarus raced to a 5-2 lead but when Sabalenka celebrated a winner too early she was called for hindrance. The Belarussians then each squandered a match point by netting a forehand. Bertens saved another before the pressure told and she served a double fault to lose the match.
In the other tie decided by the doubles, the Russians Anna Blinkova and Anna Kalinskaya had a less stressful time as they beat Jaqueline Adina Cristian and Elena Gabriela Ruse 6-3, 6-2.
Cristian had just kept the hosts in the tie by beating Veronika Kudermetova 7-5, 6-3 in the last singles.
- Spain too strong -
In Cartagena, two-time Grand Slam champion Osaka was replaced in the reverse singles by Kurumi Nara, after an error-filled loss the day before. Nara lost to Carla Suarez Navarro 6-1, 6-3 as Spain took an unassailable 3-0 lead.
"We wanted to be in Budapest so much and we are there, so I'm so happy," said the 31-year-old Suarez Navarro who is set to retire from tennis this year.
In Bratislava, Heather Watson gave Britain hope when she beat Slovakia's Rebecca Sramkova 6-0, 7-5 in the opening singles, but Anna Karolina Schmiedlova beat Harriet Dart 7-5, 6-3. Dart, who had lost a three-setter that lasted almost three hours the evening before, sat on her chair and wept in frustration.
In Biel, Switzerland, 185th ranked Leylah Anne Fernandez beat fifth ranked Belinda Bencic 6-2, 6-7 to keep Canada in their tie.
Teenager Jil Teichmann then clinched a Swiss victory beating Gabriela Dabrowski 6-3, 6-4.
"She really deserved the win," Bencic said. "Already she's a great player at 17 years old."
- Belgian passion -
Belgium won both the reverse singles to beat Kazakhstan in front of a home crowd in Kortrijk.
Elise Mertens beat Yulia Putintseva 6-1, 7-6 (7/1), and veteran Kirsten Flipkens then beat Zarina Diyas 6-3, 6-4
"You don't have this feeling very often of playing in front of a full stadium here in Belgium, said Mertens. "So you really have to treasure it."
Germany completed a 4-0 rout of Brazil in Florianopolis in a tie in which the last singles was not played. Germany did not drop a set, but star Laura Siegmund said the victory was hard work.
"Maybe sometimes it look easier than it was," she said. "We have almost no German fans, except our box, so it's not easy. Also the weather conditions... for us this was very hot."
Aryna Sabalenka and Aliaksandra Sasnovich celebrate Belarus' place in the Fed Cup finals
Kurumi Nara replaced Naomi Osaka for the singles against Spain but lost to Carla Suarez as Japan were eliminated in the Fed Cup
Belgium's team celebrated with their fans after beating Kazakhstan