Four-time champions Russia became the first team to come back from 2-0 down in a Fed Cup semi-final to complete a 3-2 triumph over Slovakia on Sunday.
Ekaterina Makarova and Elena Vesnina sealed the crucial point when they beat Dominika Cibulkova and Daniela Hantuchova 4-6, 6-3, 6-1 in the deciding doubles.
Russia are now to face either Italy or defending champions, the Czech Republic in November’s final.
Italy were leading the Czechs 2-1 when rain caused a suspension of their Palermo tie.
Makarova was praised for her efforts after she played two three-set matches on Sunday having not featured at all on Saturday when Russia slipped 2-0 down to the 2002 champions.
“She’s amazing. We were joking that she’s like a soldier,” Makarova’s doubles partner Elena Vesnina said.
“She has a bleeding knee and she won such an amazing match — one of the most emotional matches she has won. And then in the doubles, she was feeling tired, but she’s a great fighter.”
Earlier on Sunday, Makarova had pulled Russia level at 2-2, beating world No. 75 Hantuchova in a tough three-setter 6-3, 4-6, 6-4 to record her first ever win over the Slovak veteran.
In the opening rubber, Maria Kirilenko beat Cibulkova 7-5, 6-1 to reduce the arrears to 2-1.
In Palermo, former Wimbledon winner Petra Kvitova defeated Sara Errani 2-6, 6-2, 6-0 to keep defending champions, the Czech Republic alive in their semi-final against Italy.
With rain having already disrupted play, the decision was then taken to complete the tie yesterday.
Serena and Venus Williams delivered singles victories to lift the US to a playoff victory over Sweden that will keep America in the elite World Group.
Venus Williams persevered to deliver the clinching point, sealing a 6-3, 7-5 victory over Johanna Larsson on her eighth match point at Delray Beach.
“She started lifting her game, but thanks to all the support I was able to give it to the US,” said Williams, who had seven of her 11 double faults in the second set.
World No. 1 Serena Williams had put the Americans on track Saturday with a win over Larsson, and she put the 17-time champion US up 2-1 with a dominant 6-2, 6-1 win over Arvidsson on Sunday.
Serena fired 10 aces and broke Arvidsson twice in each set.
“Today I played better — I had to going up against the No. 1 player from Sweden who had a really good win over our star player in America,” said Williams, who stretched her perfect Fed Cup singles record to 10-0.
Five-time champions Spain ensured their return to the World Group after easing to a 4-0 win in Barcelona over Japan, who drop back into World Group II after just a year in the top tier.
With Sunday’s play starting with Spain 2-0 up, the tie was swiftly decided as Spanish No. 1 Carla Suarez Navarro beat Japan’s Ayumi Morita 6-3, 7-5.
In Stuttgart, Anna-Lena Groenefeld and Sabine Lisicki sealed victory for Germany in the deciding doubles against Serbia.
They saw off Vesna Dolonc and Aleksandra Krunic 6-2, 6-4 for a 3-2 triumph.