
World number one Novak Djokovic suffered a surprise quarter-final exit at the Mutua Madrid Open - and then joined Rafael Nadal in questioning the blue clay courts.
The Serbian was undone by fellow countryman Janko Tipsarevic, who racked up 30 winners on his way to an unexpected 7-6 (7/2) 6-3 victory.
Djokovic has struggled against Tipsarevic in the past - he lost to him in London last November - and Friday was no different, with the game's leading player committing 20 unforced errors on his way to a fourth loss of the year.
It was his first on the blue clay, though, and, like Nadal earlier in the week, he questioned the wisdom of the move from the normal red surface.
"I want to forget this week as soon as possible and move on to the real clay courts," he told a news conference after his loss.
"It took me at least a week to try and get used to this surface and somehow find a way to win matches and play a decent level of tennis.
"There is no discussion in my eyes, it's very simple. No blue clay for me."
Tipsarevic's reward, if it can be classed as that, is a last-four meeting with the in-form Roger Federer.
While his peers have floundered on the new surface, the Swiss has made it look easy, and did so again as he saw off David Ferrer 6-4 6-4.
Fernando Verdasco came back down to earth with a bump.
Less than 24 hours after his shock win over Rafael Nadal, Verdasco was thrashed 6-1 6-2 by Tomas Berdych.
The Spaniard had taken more than three hours to upset Nadal on Thursday, posting his first win over his compatriot in 14 attempts, and he cut a weary figure against Berdych's powerful strokes.
Berdych, who lost just two games in dispatching Gael Monfils in his previous match, gained control early on control and refused to relent as he eased to victory.
The Czech lost just nine points on serve in the match and has yet to lose his delivery in three outings so far on the Caja Magica's blue clay.
"I feel great," Berdych told atpworldtour.com. "I'm in another semi-final, [the] second in a row. To beat Fernando made me feel great. It is always tough to beat Fernando, even though the score looks quite easy. It's not easy to beat a Top 20 player and he played great yesterday [against Rafael Nadal]."
Berdych will face Juan Martin Del Potro on Saturday for a place in the final.
"I'm expecting a really tough match," added Berdych.
"To play Juan Martin is always tough, he's a great guy and he knows how to win the Grand Slams. He's definitely back after his [wrist] injury.
Del Potro remains unbeaten on clay in 2012 following a comfortable victory over Alexandr Dolgopolov in his quarter-final.
The Argentine, a winner in Estoril last week, made it 10 wins out of 10 on the surface with a 6-3 6-4 triumph on Friday. He has yet to drop a single set on clay this season.
Del Potro needed just 84 minutes to reach the last four, breaking his opponent's serve three times in total.
Dolgopolov's 'mix it up' game had been tipped in some quarters to cause problems but in the end it was Del Potro's power play which prevailed on the slick surface.
 



