Novak Djokovic survived four match points and Roger Federer came back from two sets to love down to progress to the French Open semi-finals.
Novak Djokovic and Roger Federer survived five-set struggles at the French Open on Tuesday to set up a mouth-watering semi-final where the Swiss legend will attempt to shatter the world No.1's grand slam dream.
Top seed Djokovic saved four match points against Jo-Wilfried Tsonga before pulling off a nail-biting 6-1 5-7 5-7 7-6 (8-6) 6-1 quarter-final win.
Third seed Federer reached a record-equalling 31st grand slam semi-final when he survived a brutal barrage from frail Argentine Juan Martin del Potro before prevailing 3-6 6-7 (4-7) 6-2, 6-0 6-3.
After his triumphs at Wimbledon, the US Open and the Australian Open, Serb star Djokovic is bidding to become just the third man to hold all four grand slam titles at the same time and the first in 43 years.
His win over Tsonga made it 26 straight match victories in grand slams, but seldom has he been run so ragged as he was at times by the powerful Frenchman, who had let slip four match points in the fourth set.
The defeat meant Tsonga's dream of becoming the first Frenchman to win at Roland Garros since Yannick Noah in 1983 had been cruelly shattered.
"He was the better player for most of the match and I was fortunate to come back from four match points down. It was an incredible match," said Djokovic, who had needed five sets to beat Italy's Andreas Seppi in the fourth round.
Heartbroken Tsonga said: "I did what I said I would and gave everything. I came close and I would have loved to have won. It's a shame because I was pretty close, but at the end I had no energy left.
Federer, the 16-time grand slam title winner and 2009 champion in Paris, came back from two sets to love down for the seventh time in his career and will take on Djokovic for the 26th time with a place in Sunday's final at stake.
The result was cruel luck on the 1.98m Del Potro who had looked on course for a straight sets win after unleashing a brutal wave of power-hitting off both wings which left Federer floundering in the first two sets.
However, his hopes were finally sabotaged by a recurrence of the knee injury which has plagued him in Paris and which left him struggling to move by the end of Tuesday's match.
"I knew Juan Martin's knee was bothering him and was trying to finish the rallies quickly," said Federer, who has pulled level with Jimmy Connors' mark of 31 grand slam semi-finals.
"I knew it would be a big fight today. I played well tactically and was strong mentally because there wasn't a lot in it."
The two remaining quarter-finals will take place on Wednesday when six-time champion Rafael Nadal meets fellow Spaniard Nicolas Almagro boasting a 7-0 career advantage.
Fourth seeded Andy Murray faces Spain's David Ferrer, defending a 5-4 series lead.
