World number one and defending champion Novak Djokovic crashed out of the Madrid Masters on Friday, vowing never to return to play on the tournament's controversial blue clay.
Djokovic lost 7-6 (7/2), 6-3 to Serbian compatriot Janko Tipsarevic, his quarter-final defeat coming a day after an equally frustrated world number two Rafael Nadal had lost to fellow Spaniard Fernando Verdasco.
"I want to forget this week as soon as possible and move on to the real clay courts," said the top seed, who beat Nadal a year ago for the trophy.
"They can do what they like, I won't be here next year if this clay stays."
Nadal also insisted on Thursday that he, too, would not play the Madrid tournament if the blue clay remains in place in 2013.
In stark contrast, third seed and 2009 winner Roger Federer became the only elite survivor after another effortless performance in a 6-4, 6-4 defeat of fifth seed David Ferrer.
The Swiss star will next play Tipsarevic, whom he has beaten four times.
Federer was unwilling to get dragged into the controversy over the court conditions.
"If you want to be a good claycourt player, you must be able to play everywhere," said Federer.
"Madrid has taken a gamble with blue clay. It's always a little different here because of the altitude and we must sit down with the other players to discuss it.
"It is slippy, there's no doubt about that but that has been the case here for a few years. They haven't yet found the perfect balance. Our job each day is to adapt to the conditions that we face."
Federer now stands 26-3 on the season, playing for the first time after a six-week break.
The 16-time Grand Slam champion could move to second in the world behind Djokovic should he win the title on Sunday.
Earlier on Friday, tournament supremo Ion Tiriac had been forced to apologise for the anger felt by the players towards the blue surface.
"The court is slippery and I apologise," said the former Davis Cup player.
"We wanted to make sure that we had no player injuries, no ankle problems. As a result, the court experts rolled the base with too much pressure. When the blue sand was put on top it was unable to meld with the base, creating the slippage."
But Tiriac said that after striking a maintenance deal with the city of Madrid, the blue courts will remain in place year-round at the Caja Magica and will eventually be as comfortable to play on as traditional red clay.
Djokovic saved three match points in the penultimate game against Tipsarevic on Friday -- the first two with aces -- as he held on for 3-5.
But Tipsarevic came through for the upset on his fourth chance a game later as Djokovic lifted a backhand out.
"Janko played a great match. It was one of his best events. I hope he can go all the way. I missed chances in the opening games on return," added Djokovic.
"Any time I had a chance, he delivered his best shot. You cannot predict the court here, anything is possible."
Tomas Berdych brought Verdasco crashing back to earth as the sixth seed produced a 6-1, 6-2 quarter-final win over the Madrid-born 15th seed.
The Czech will next play Argentine 10th seed Juan Martin del Potro, who put out Ukrainian Alexandr Dolgopolov 6-3, 6-4, just a week after winning the title in Estoril.