Murray looked on his way out when he was broken for 3-2 in the final set of his third-round encounter with Philipp Kohlschreiber of Germany, but after a match of numerous ups and downs, the world No 8 hit back. When bad light stopped play at 9.39pm at Roland Garros, the pair were level at 3-6, 6-3, 6-3, 4-6, 7-7.
Murray should have been home and hosed at least an hour before that. He led by a service break in all five sets but only converted the advantage twice.
Each time, he let world No 24 Kolschreiber off the hook and it was only Murray's refusal to give in that means he will return to the court today to try to finish the job.
With his movement seemingly restricted, mostly when moving to his right, Murray's mood flitted from one of trying to get things done quickly by smashing winners, to just getting off the court, even if it meant losing.
When he was focused, his ball-striking was as good as it had been in Rome last month when he pushed Rafa Nadal hard in the semi-final. When he allowed his concentration to drift, he slapped the ball long and wide and threw in too many double-faults.
To his credit, Kohlschreiber, who beat Murray easily when they played on clay in Monte Carlo a few years ago - a match that saw Murray jeered by sections of the Monaco crowd - was solid throughout and traded blows with the Wimbledon champion, especially through his fluent one-handed backhand.
Murray hit his backhand down the line with authority but was too often guilty of squandering positions of control. He needed treatment to both thighs midway through the final set, but, as so often when the chips are down, he dug in when he needed to.
At 6-6, facing break point, he played a perfect backhand to save it and then a beautiful drop volley was celebrated with a double fist pump, Murray knowing there was time for only one more game.
At deuce he had a chance to get to match point but missed a backhand. Given everything, he was probably grateful to get off the court with his hopes in the tournament still alive.
Elsewhere, a ripple went around Roland Garros yesterday when Nadal made an admission that could affect his chances of winning a ninth French Open title here a week today. The world No 1 had just beaten Leonardo Mayer of Argentina 6-2, 7-5, 6-2 with only a minor wobble in the second set when he removed his shirt to reveal a strip of protective tape running up his lower back.
Four months after he was struck down by back trouble in the final of the Australian Open, a match he lost to Stan Wawrinka, Nadal said he has been feeling some pain in his back from the start of the tournament and though he later tried to play down its significance, he will now have to rely even more on his outstanding mental strength if he is to win here for a ninth time in 10 years.
Though Nadal won't say it in public, the only man he really fears on clay, over five sets, is Novak Djokovic, who plays Jo-Wilfried Tsonga in the fourth round today. Perhaps it was a ruse to take some of the pressure off, but it seemed more like a genuine complaint from a man who rarely talks about his injuries in any detail.
"I don't usually lie," said Nadal who now plays unseeded Serb Dejan Lajovic. "My back was hurting a little, and this is what I said on day number one; during the second day, as well. So that's why I served more slowly since I started feeling the pain. I had the problem in Australia. It's real. But hopefully [it is] not [a concern]."
His first-serve speed may have been down, but the only moment of real concern for Nadal came when he let slip an early break in the second set and had to serve to stay in it at 4-5. After righting the ship by winning the next three games, he eased through the third without any trouble.
It is the 10th straight time the Spaniard has made the last 16 here - a record, of course - and he has now won 31 consecutive matches here, dating back to his only loss, to Robin Soderling in the fourth round in 2009.
Having impressed in the second round against Austrian youngster Dominic Thiem, Nadal has yet to drop a set this time and if he can shake off the injury, then he remains the man to beat.
"I'd rather not talk about my back," he said. "I've reached week number two. I'll do my best, I'll play the best I can, I'll put up a good fight to try and win. My back is not that important."
Lajovic took advantage of a lacklustre performance from American Jack Sock to advance to the fourth round of a Grand Slam for the first time while another American, Donald Young, went down in five sets to Guillermo Garcia-Lopez of Spain, 6-2, 6-4, 2-6, 67 (4-7), 6-4.
Garcia-Lopez's next opponent will be Gael Monfils, the flamboyant Frenchman who began the tournament with a stunning exhibition of dancing, and who yesterday beat Italy's Fabio Fognini in a bizarre match that had more twists and turns than a roller-coaster.
For a five-set match, it lasted a relatively short three hours, 24 minutes but it managed to pack in 19 breaks of serve and 137 unforced errors.
The pair both took medical time-outs and Monfils basically tanked the fourth set after going a break down.
In the fifth, though, with the crowd on Court Suzanne Lenglen roaring their support, he bounced back, cranked up his serve and won through 5-7, 6-2, 6-4, 0-6, 6-2.
It was classic Monfils, as were his comments when asked what happened in that curious fourth set.
"I was like starting to struggle a little bit, like not cramping, but feeling really tired," Monfils said.
"I think all the fatigue was coming up. I wanted to serve first in the fifth so the only option I had is to take 6-0. Why should I make any effort?
"I think it is never easy to drop a set. The fourth, I was out of rhythm a little bit. And just to try to come back for the fifth is never easy and definitely the crowd helped me a lot."
Fifth seed David Ferrer eased past Andreas Seppi of Italy in straight sets while 19th seed Kevin Anderson was leading Ivo Karlovic by a set when the Croatian had to quit because of a lower back problem.
Today's action will centre around the two big matches, the clash between Djokovic and Tsonga and Roger Federer's meeting with Ernests Gulbis, the man who last year criticised the top players for being boring. Their match is unlikely to be that.
Meanwhile, Jamie Murray's French Open run came to an end as he and Australian partner John Peers were well beaten by Bob and Mike Bryan in the men's doubles.
Murray was playing in the third round at Roland Garros for the first time but defending champions the Bryan brothers are the dominant force in doubles, the American top seeds needing just 49 minutes to wrap up a 6-3 6-1 victory.