Stuttgart - Italian Fabio Fognini upset second seed Nikolay Davydenko 6-1, 3-6, 7-5 on a rainy Friday at the Mercedes Cup to reach the fourth semi-final of his career.

The 22-year-old will face off Saturday on the clay of the Weissenhof club against fourth seed Victor Hanescu, who turned in another steady performance to oust lucky loser Alexandre Sidorenko of France 7-6 (7-2), 6-4.

The last two Germans in the field were battling the weather with rain disrupting the start of the quarter-final between 32-year-old Nicolas Kiefer, playing the event for the first time in a dozen years and Polish qualifier Lukasz Kubot, losing finalist to Novak Djokovic in Belgrade two months ago.

Davis Cup player Mischa Zverev, who teamed with Kiefer last weekend in a 3-2 loss in Spain, was to face Jeremy Chardy of France.

The match between Fognini and Russia's 11th-ranked Davydenko was interrupted in the third set by the weather, with the Italian ranked 67th coming back out to dominate in the closing stages after losing to Davydenko in May, 2008 in Warsaw.

The outsider broke five times as the Russian favourite lost his eighth match of the season against 20 victories.

Davydenko, who suffered a Janaury heel injury which kept him away for two months, was unable to reach his third semi of the season after Barcelona and Estoril on the clay.

But the former top five player will try his luck next week in Hamburg, determined to remain in Europe for as long as possible before transferring to North American hardcourt in the run-up to the US Open.

"I need ranking points and I need results, I don't need to change surfaces right now," said the holder of 14 career titles. "I want to stay in Europe for as long as I can.

"I'm not that keen on heading to the US until absolutely necessary. It's a lot easier and more comfortable for me over here. To me, the surface doesn't matter, I just want to keep playing matches."

Romanian Hanescu, now the last seed left in contention, is looking to add a title to the Gstaad honours he collected last summer, the first trophy success of his career.

The 27-year-old, 17-18 on the season, played his last semi-final in St. Petersburg last October. (dpa)