Novak Djokovic and Roger Federer survived five-set encounters to progress to the semi-finals of the French Open at Roland Garros.
Top seed and world number Djokovic saved four match points in the fourth set of his titanic tussle against home favourite Jo-Wilfried Tsonga to prevail 6-1 5-7 5-7 7-6 (8/6) 6-1.
Tsonga, playing in his first quarter-final at Roland Garros, looked out of sorts as he lost the first set in just 21 minutes, but the Frenchman produced a spirited comeback to take the next two sets.
But he then spurned match points in the fourth set before eventually running out of steam, leaving Djokovic to set up a semi-final against Federer.
The Serbian was not at his best for large parts of this match, and Tsonga will rue the opportunities he missed, but the victor showed exactly why he is ranked number one in the world by winning the killer points and holding his nerve while under immense pressure in front of a partisan crowd on Philippe Chatrier.
Tsonga had promised to "fight like a lion" but he performed more like a scared kitten in the opening set.
He held his first service game but Djokovic moved into a 3-1 lead after the Frenchman double-faulted at 0-40.
Another break followed after Tsonga found the net with a forehand and Djokovic held to take the set 6-1.
Djokovic's dominance continued as he broke Tsonga early in the second set, but the fifth seed steadied the ship by holding for the first time since his opening game.
The Tsonga fightback then began as he grew in confidence. A long backhand from Djokovic gave the 27-year-old his first break point and he did not disappoint, powering down a fierce backhand volley to level.
Tsonga held before clinching the second set at the third time of asking when Djokovic over-hit a backhand.
Tsonga wasted a chance to make early inroads in the third set and Djokovic pounced in the following game to move 2-1 ahead.
The Serbian lost his next service game to allow Tsonga to level at 2-2, however.
Djokovic then threw away two further break points and Tsonga made him pay by clinching the third 7-5 after overcoming the favourite with a volley that was greeted with a loud roar by the partisan Parisien crowd.
The top seed was handed two break points early in the fourth but Tsonga responded with two unreturnable serves. Tsonga showed yet more incredible resolve to send down another ace when Djokovic had a break point in the ninth game and he sent down another to leave the Serbian serving to stay in the match.
Five-time major winner Djokovic wilted under the pressure, gifting Tsonga two match points but he did not take them.
Tsonga spurned another two chances to clinch the match in the 12th game and the fourth set went to a tie-break, which Djokovic won when the fifth seed ploughed into the net.
Tsonga, physically and mentally drained from the encounter, seemed rattled and crumbled easily in the fifth.
Djokovic broke twice and clinched the match with a precision backhand to conclude the epic clash after four hours and nine minutes.
Earlier, Federer Federer fought back from two sets to love down for the seventh time in his career to defeat Juan Martin Del Potro 3-6 6-7 (4/7) 6-2 6-0 6-3.
For two sets it looked like the 16-time grand slam champion was on his way home, with Federer particularly out of sorts in the opener on a cool and damp Court Suzanne Lenglen.
But Del Potro has been struggling with a left knee injury and, after he edged a very tight second on a tie-break, his movement became gradually worse.
The Argentinian's decline coincided with a marked improvement from Federer, and in the end the third seed came through the last three sets reasonably comfortably.
The 30-year-old had struggled to find his best form in all his previous four matches, dropping sets in three of them despite not facing anyone ranked higher than 78th.
In the first set he was particularly off colour, making a host of unforced errors, and Del Potro was able to play well within himself and still win it easily.
The second looked like being the key to the match. Federer, who had beaten Del Potro five times in a row since losing to him in the US Open final in 2009, was battling himself, letting out a roar of frustration when he put another forehand over the baseline in the fifth game.
He still managed to break, though, this time a forehand proving too good for Del Potro, only to give it straight back with the tamest of forehands into the net.
Both men were pushing for the advantage. Del Potro had a chance in the eighth game but just missed with a forehand, then in the next game Federer brought up three chances but could not take any of them.
He thought he had with a forehand that was called good but it was over-ruled by umpire Pascal Maria.
In truth the quality of the match had not been that high, but it rocketed in the tie-break, and it was Del Potro who climbed the highest.
The raw power of the Argentinian was simply too much for Federer, with the ninth seed winning some brutal rallies despite the best efforts of the 2009 champion.
Federer had not fought back from two sets down to win since a first-round match at Wimbledon in 2010 against Alejandro Falla, but he made the best possible start to the third with an early break when Del Potro double-faulted.
And it soon became clear the 23-year-old, who has had heavy strapping on his left knee all tournament, was struggling.
The fourth set was a breeze for Federer, but he still had to save two break points at the start of the decider, both with tremendous forehands, as Del Potro steeled himself for one big effort.
The crucial break came in the fourth game, a curling forehand winner down the line leaving his opponent flat-footed, and he had little trouble holding on to his advantage, sealing victory on his second match point when Del Potro's forehand hit the top of the net and drifted wide.
The victory put Federer into a 31st grand slam semi-final, equalling the record set by Jimmy Connors, while he has also now reached at least the last four seven times or more at every slam.
