World number two Nadal was pushed every inch of the way by the Russian fourth seed in a tense tussle that lasted 3 hours and 38 minutes.

Nadal saved set point in the first set before Davydenko lost his nerve in the tie-break.

Davydenko levelled the tie after Nadal had failed to serve out the second set as the Spaniard dropped his first set on clay this year.

At 4-4 in the decider, Nadal broke to love before serving out the match.

Both players were given a standing ovation at the Foro Italico's centre court as Nadal extended his record winning streak on clay to a staggering 76 matches and clinched a place in Sunday's final against Fernando Gonzalez.

Chilean sixth seed Gonzalez defeated Italian wild card Filippo Volandri -- who knocked out world number one and top seed Roger Federer in the third round -- 6-1, 6-2 in just 67 minutes, leaving him far fresher than Nadal for Sunday's showpiece.

Nadal, whose last defeat on clay was back in April 2005 against Russian Igor Andreev in the Valencia quarterfinals, said his victory was not only a test of his physical strength.

"There were some very tough moments for me and I had to stay tough mentally," said the 20-year-old left-hander who is aiming to become the first player to win the Rome Masters three times in a row.

"He gave me a very, very tough match, but I always believed I would get through it.

"Tomorrow I will have another very difficult match, but I am very motivated."

Davydenko saluted Nadal for his never-say-die spirit.

"He's amazing -- he chases every ball and physically he is great," said the 25-year-old world number four.

"In the first two sets I was playing in a more controlled way, but I tired in the final set and he kept coming back at me.

"He kept putting more and more top spin on his shots and moving me all around the court.

"I think the difference between us was physical. It's something I need to improve on as when I tire my concentration is not as good."

Gonzalez, runner-up in this year's Australian Open, insisted the pressure was all on Nadal for the final.