Andy Murray did things the hard way again as he defeated unseeded Juan Ignacio Chela 7-6 (7/2) 7-5 6-2 to reach the semi-finals of the French Open for the first time.
The world number four fought back from two breaks down to win the first set then squandered the same advantage in the second before eventually battling through.
The prize for Murray, who looked mentally and physically drained after an eventful few days in Paris, is a last-four clash with five-time champion Rafael Nadal on Friday.
Murray, again playing on Court Suzanne Lenglen, had lost the first five games of his previous match against Viktor Troicki as he struggled with the effects of a torn tendon in his right ankle and it was not much better today.
The Scot appeared to be moving okay but he did not deal well with the blustery conditions and, from 1-0 up, lost four straight games to experienced campaigner Chela.
It was the third year in a row in which the Argentinian had found himself facing Murray at Roland Garros and, although he had lost both times, last year was far from straightforward.
Chela was simply not missing from the baseline but the British number one dug deep to retrieve one break before saving two set points on his own serve, the second with a superb dinked backhand.
Still Chela had a chance to serve out the set but he let Murray back in by hitting a double-fault on set point and, after he missed a between-the-legs shot by a whisker, the Scot levelled at 5-5 with a superb forehand winner.
Still it was not straightforward as the 24-year-old was forced to save two more break points to set up a tie-break. This time he did take control, winning five points in a row to lead 5-1 and then taking his first set point.
Unbelievably the second set adopted the same strange pattern, although this time it was Murray who took the lead and was then pegged back after squandering opportunities.
The fourth seed broke immediately and, after saving four break points in the second game, pulled 4-1 ahead.
Chela, who lost to Tim Henman on his only previous appearance in the last eight in 2004, must have been wondering how he was behind in a match in which he had had so many chances.
He looked weary and when two more breaks left Murray serving for the set at 5-2, it seemed the match as a contest was all but over.
There was a big twist to come, though, as the Scot missed two set points on his own serve, another on Chela's and was then broken for the second time in a row as the 31-year-old made it 5-5.
The Argentinian now had a new lease of life and if he could have held he would have been favourite to level the match but back came Murray and this time he served out the set with an ace on his fifth opportunity.
The Scot certainly would have wanted to finish the job in three sets and he made the perfect start to the third with yet another break of serve as Chela double-faulted twice.
Murray at last took full control of proceedings and when he broke for a 5-2 lead, pounding Chela with huge groundstrokes, the end was nigh.
Still there was time for the Argentinian to create another break point but the 24-year-old saved it with an ace before wrapping up victory with a drop shot in two hours and 53 minutes.