Dmitry Tursunov fought off a remarkable Andy Roddick comeback to seal a superb victory and send Russia into the Davis Cup final at the expense of the USA.
Tursunov showed all his resolve to secure a dramatic victory
The home crowd proved inspirational for Tursunov in the opening sets as he secured a valuable 2-0 lead, only for a dogged Roddick to fight back to 2-2.
The fifth set was a marathon, with both players failing to consolidate breaks.
But Tursunov held his nerve to win 6-3 6-4 5-7 3-6 17-15, securing a 3-1 tie lead and a final against Argentina.
The Russian's win was made all the more stunning after bouncing back from the disappointment of wasting three match points in game 24 of the fifth set, digging deep to see off a clearly exhausted Roddick.
It was a dramatic conclusion to a nip-and-tuck semi-final that lasted four hours and 49 minutes and could have gone either way.
Bob and Mike Bryan's doubles win had kept the USA in the hunt after they beat Mikhail Youzhny and Dmitry Tursunov in the doubles on Saturday.
Marat Safin and Youzhny had seen off Roddick and James Blake on Friday to give Russia a 2-0 lead.