Determined Novak Djokovic refuses to buckle under Jo-Wilfried Tsonga assault

The history men march on. Novak Djokovic, who is attempting to become the first man for 43 years to hold all four Grand Slam titles, and Roger Federer, who breaks or equals records with almost every victory, reached the French Open semi-finals here last night, but only after winning five-set matches they could so easily have lost.

Djokovic saved four match points in the fourth set before beating Jo-Wilfried Tsonga 6-1, 5-7, 5-7, 7-6, 6-1, while Federer won from two sets down for the seventh time in his career to beat Juan Martin del Potro 3-6, 6-7, 6-2, 6-0, 6-3. The 25-year-old Serb and the 30-year-old Swiss, right, will meet on Friday, the fourth time they have faced each other in the semi-finals in the last five Grand Slam tournaments.

On another cold and damp day – it was raining persistently in the latter stages of both matches – spectators were warmed by two thrilling contests, which took place simultaneously on the two main show courts. While fortune favoured Federer on Court Suzanne Lenglen as Del Potro struggled after the first two sets with the recurrence of a knee injury, there was no doubting Djokovic's courage on Court Philippe Chatrier in front of a passionate home crowd.

Like Federer, Djokovic has not always been at his best in this tournament and for the best part of four sets Tsonga dictated with his bold attacking play. In the past 18 months, however, Djokovic has proved time and again that he has the nerve to handle a crisis.

The world No 1 saved two match points when he served at 4-5 in the fourth set and two more two games later. He was rock-solid on each occasion, putting Tsonga under enormous pressure with the quality of his ball-striking. Djokovic said afterwards that the key on the match points had been to be "mentally tough and believe in your shots".

Tsonga saved two set points in the tie-break, but when the Frenchman put a backhand in the net on the third Djokovic roared in celebration. The deciding set was almost a formality after the Serb made an early break.

At the end, after more than four hours, a disconsolate Tsonga sat in his chair with his head buried underneath a towel. "I was tired, frustrated, disappointed," he said later. "You get all kinds of feelings going through your mind. You want to break your racket. You want to shout. You want to cry. You want to laugh and say: 'Oh, come on, that's a joke. How could I lose this match?'"

Del Potro refused to blame his defeat on the injury to his heavily bandaged left knee, but from the third set onwards his movement appeared increasingly impaired. Until that point Federer had struggled to find his rhythm under an onslaught from Del Potro's ferocious groundstrokes, just as he had when the Argentine beat him in the US Open final three years ago. The world No 9's bludgeoning forehand, struck flat with enormous force, is arguably the most powerful in the modern game.

Federer, who admitted afterwards that he had found the slow conditions difficult, let his frustration show in the second set. He slapped a loose ball away in anger – fortunately for the Swiss there was nobody in his line of fire – and shouted to the crowd to "shut up" after they became particularly noisy. Del Potro took the first set with breaks in the third and seventh games and the second by winning the tie-break 7-4.

The Argentine appeared on the brink of his biggest victory since his comeback last year after a serious wrist injury, but it soon became clear that his knee was troubling him again. He called for a trainer and a doctor in the third set, won just eight points in the fourth and offered only marginally greater resistance in the decider after having the knee rebandaged.

It was a second major disappointment for Del Potro here against Federer. Three years ago he led the Swiss by two sets to one in the semi-finals before letting victory slip from his grasp.

Federer, who beat Jimmy Connors' mark of Grand Slam victories earlier in the tournament, is through to the 31st Grand Slam semi-final of his career, which equals another of the American's records. He is also the first man over the age of 30 to reach the semi-finals here since Andres Gomez in 1990.

The forthcoming encounter with Djokovic promises more drama. Federer lost after scorning two match points in his US Open semi-finals against the Serb in both 2010 and 2011, while his only victory in their last four Grand Slam semi-final meetings was here 12 months ago, when he ended Djokovic's unbeaten run since the start of the year.

Australia's Sam Stosur and Italy's Sara Errani became the first women to reach the semi-finals. Stosur, through to the last four here for the third time in four years, beat Slovakia's Dominika Cibulkova 6-4, 6-1, while Errani beat Germany's Angelique Kerber 6-3, 7-6. It was the world No 24's first victory over a top 10 player in 29 attempts.

French Open results

Roland Garros, Paris: Quarter-finals

Men's Singles R Federer (Swit) bt J M Del Potro (Arg) 3-6 6-7 (4-7) 6-2 6-0 6-3; N Djokovic (Ser) bt J-W Tsonga (Fr) 6-1 5-7 5-7 7-6 (8-6) 6-1.

Women's Singles S Stosur (Aus) bt D Cibulkova (Slovak) 6-4 6-1; S Errani (It) bt A Kerber (Ger) 6-3 7-6 (7-2).