MONTE CARLO (AFP) - Russian fourth seed Nikolay Davydenko reached his fifth semi-final of 2008 with a gruelling 6-3, 4-6, 7-5 victory over Davis Cup teammate Igor Andreev in the last eight of the Monte Carlo Masters on Friday.

Davydenko, who has already won the Miami Masters title this season, will now take on either triple defending champion Rafael Nadal or David Ferrer for a place in Sunday's final.

But his 2hr 45min win on Friday was desperately mediocre with both players plagued by errors; in the second set alone there were seven breaks of serve in 10 games.

Davydenko recovered from falling 1-3 down in the opening set before breaking his 24-year-old opponent in the fifth and seventh games.

After their woeful second set, Andreev was soon ahead again at 3-1 in the decider before Davydenko had the opportunity to serve out the match in the ninth game.

But Andreev secured the 14th break of the quarter-final to go to 4-5 and then wasted two break points in the 11th before Davydenko broke again in the 12th to claim victory.

In a brutal summary of the tie, Davydenko sent down 61 unforced errors to Andreev's 54.

Later Friday, world number one Roger Federer, the runner-up here for the last two years, takes on Argentine sixth seed David Nalbandian for the 17th time in his career.

The two are tied at eight wins each but the muscular Nalbandian has won the last two encounters.

The winner of that quarter-final will tackle either Serbian third seed, and Australian Open champion, Novak Djokovic or Monte Carlo debutant Sam Querrey who is bidding to become the first American to make the semi-finals since Vince Spadea in 2003.

Defending champion Nadal, who is hoping to be the first man since 1914 to win four Monte Carlo titles in a row, faces Spanish compatriot Ferrer, the fifth seed.

Nadal has a Monte Carlo record of 21 wins in 22 matches and has won 95 of his last 96 claycourt ties in the last three years.