Svetlana Kuznetsova saved two match points in the second set tiebreaker before beating Francesca Schiavone 4-6, 7-6, 7-5 in the first reverse singles on Sunday to give Russia their third Fed Cup title in four years.
Kuznetsova's victory gave the home team an unassailable 3-0 lead over last year's surprise winners Italy in the final at Moscow's Luzhniki arena.
Heavy favourites Russia had enjoyed a commanding 2-0 lead after day one when U.S. Open finalist Kuznetsova and world number five Anna Chakvetadze both won their singles.
Kuznetsova crushed Italy number two Mara Santangelo 6-1, 6-2 on Saturday, but looked frustrated for much of her match with the combative Schiavone.
The Russian had to save two match points in the second set tiebreaker to force the third set, where she broke in the ninth game with the help of two net-cords to lead 5-4.
Schiavone, the heroine of Italy's 3-2 semi-final victory over France in July when she won all three of her matches, was not to be denied, however, as she battled back to level at 5-5.
Kuznetsova had the last word, though, gaining another break in the next game, then coming back from 0-30 to win the last four points in the match and secure victory after two hours 45 minutes.