Italy ended Russia's two-year reign as Fed Cup champions on Sunday.
Francesca Schiavone won the tie-clinching point with victory over Anastasia Pavlyuchenkova in the fourth rubber at Castellaneta Marina.
Schiavone battled her way to a 7-6 (9/7) 4-6 6-2 win over Pavlyuchenkova, who came in to replace the out-of-sorts Anna Chakvetadze, to give her team an unassailable 3-1 lead in the tie.
They went on to win the dead doubles rubber too to finish 4-1 victors.
Earlier in the day Svetlana Kuznetsova had given the Russians hope of overturning their 2-0 deficit from the opening day, crushing Flavia Pennetta 6-0 6-3 in just 73 minutes.
Italy, who won the trophy in 2006 but then lost the 2007 final to Russia, will now host USA in November's final.
The Americans came from 2-1 down to win 3-2 on the carpet in Brno.
Lucie Safarova had put the Czech Republic ahead by winning the first of the reverse singles against Bethanie Mattek-Sands. Safarova won 6-3 6-1.
But teenager Alexa Glatch continued her dream Fed Cup debut with a 6-2 6-1 victory over Petra Kvitova - her second singles win of the weekend.
That meant the tie would be decided in the doubles and the US pairing of Liezel Huber and Mattek-Sands again showed terrific fight to come from a set down and beat Iveta Benesova and Kveta Peschke 2-6 7-6 (7/2) 6-1.
In the play-offs, Ukraine and Serbia completed emphatic victories to confirm their places in World Group I for the first time.
Ukraine powered to a 5-0 win over Argentina, Alona Bondarenko sealing victory with a 6-1 6-2 win over Jorgelina Cravero.
Further comfortable successes followed for Olga Savchuk, 6-2 6-1 over Aranza Salut, and Mariya Koryttseva and Savchuk, 6-2 6-0 over Maria Irigoyen and Paula Ormaechea in the doubles.
Serbia completed a 4-0 win over Spain thanks to wins for Jelena Jankovic and Ana Ivanovic, although both were taken the distance.
Jankovic prevailed against Anabel Medina Garrigues 6-3 3-6 6-3 and Ivanovic saw off Maria-Jose Martinez Sanchez 3-6 6-3 7-6 (7/0)
The doubles rubber was abandoned due to rain and darkness.
Germany found the going rather tougher against China before they eventually sealed a 3-2 win.
Trailing 2-0 at the start of the day, China recorded back-to-back wins courtesy of Jie Zheng and Shuai Peng to take the tie to a deciding rubber. Zheng beat Anna-Lena Groenefeld 7-5 6-4 and Peng was a 6-2 2-6 7-5 winner over Tatjana Malek.
But Groenefeld and Sabine Lisicki held their nerve in the doubles to recover from a set down and claim a 4-6 7-5 6-2 win.
An Amelie Mauresmo-inspired France fought back from 2-1 down to keep their place in the World Group with a 3-2 win over Slovakia.
After Alize Cornet lost 6-2 5-7 6-4 to Dominika Cibulkova, Mauresmo set about hauling her team back into the tie, first beating Daniela Hantuchova 7-5 6-4.
She then teamed up with Nathalie Dechy to beat Cibulkova and Hantuchova 4-6 6-1 6-4.
In the World Group II play-offs, Belgium, Estonia and Poland - who put Great Britain out of the competition back in February - were 3-2 winners over Canada, Israel and Japan respectively, while Australia beat Switzerland 3-1.