Russia into final

The California-based Russian, who replaced Mikhail Youzhny for the first reverse singles, could barely put a foot wrong, building up a two-set lead before the American fought back in the third and fourth to force the deciding set.

The win gave Russia an unassailable 3-1 lead in the three-day tie.

James Blake beat Marat Safin 7-5 7-6 in the fifth, dead rubber for a 3-2 final score.

After wasting three match points in the 24th game, Tursunov finally broke Roddick's serve in the 32nd game to clinch a dramatic victory after four hours 48 minutes.

"I didn't know I was going to play until the last minute. It was only this morning our captain Shamil Tarpishchev told me of his decision," said Tursunov, who was preferred to world number five Nikolay Davydenko.

"I didn't have much time to prepare, to work out a strategy for the match. I had some ideas of how to play him. It worked for the first two sets but not for the next two. In the fifth set I had no strategy, just tried to fight back."

The fifth set equalled the Davis Cup record for the highest number of games since the world group was introduced in 1981.

Safin and Youzhny had put the Russians up 2-0, beating Roddick and Blake respectively in the opening singles on Friday before the U.S pulled within a point by winning Saturday's doubles.

It was Russia's first victory over their former Cold War adversaries in Davis Cup after they lost two previous ties, including the 1995 Moscow final on a similar clay surface.

The Russians will host Argentina in the final in Moscow in December after the South Americans took an unbeatable 3-0 lead against Australia in the other semi-final in Buenos Aires.

After going two sets down, Roddick found another gear as the momentum seemed to shift in his favour.

When he broke the Russian's serve in the 11th game to nudge 6-5 ahead, it looked like the match was virtually over.

However, the 22nd-ranked Tursunov, urged on by a raucous 11,000-strong home crowd including former Russian President Boris Yeltsin, broke right back to prolong the contest.

Roddick looked to be in trouble several times late in the fifth set but escaped thanks to his booming serve.

Tursunov came out the stronger in the end as he finally secured victory by breaking the U.S. Open finalist in the last game with a clean backhand pass down the line.

"I don't know if it was the crowd that lifted me up in the fifth set or what," said the Russian.

"We both wanted to win and fought hard but I just never gave up and believed in myself.

"Besides, Marat was crying that he didn't want to play the deciding match and asked me to finish the tie," he added with a smile.

Roddick was visibly disappointed. "Being honest, I'm not feeling a whole lot of positive things right now," he said.

"Davis Cup losses are the toughest to take because you're not playing for selfish reasons. You feel like you let your team mates down, your country down. It's tough."