Yesterday, he produced one of his best performances on a clay court to beat Spain's Fernando Verdasco 6-4, 7-5, 7-6 and set up a match with Gael Monfils. The Frenchman is now a quarter-final opponent but Murray also considers him to be his favourite player to watch and "maybe the best athlete we've had in tennis".
If the Scot plays the way he did against Verdasco, who grew up while playing on the red clay in Spain, then he will have a fighting chance to equal his best showing in Paris: a semi-final appearance in 2011.
The smile on his face at the end and the way he stuck to his task in the third set of his match yesterday, when he gave up an early break before coming through the tie-break 7-3, proved that Murray is enjoying himself, even if his body language would suggest otherwise at times.
"I got a bit nervous at the end," said Murray. "But I think this was my best performance of the tournament and I'm glad to get through."
Having squeezed past Philipp Kohlschreiber 12-10 in the final set in the previous round - a match which only finished on Sunday - Murray faced another quick turnaround to be ready for Verdasco. However, he looked confident from the start and his game plan soon became clear as he tried to take the attack to the Spaniard, crunching ground strokes on both wings and then throwing in the odd drop shot.
"I was tired after the match against Kohlschreiber," he said. "It was mentally draining as well when you don't have that day to recover and you're coming back on court 7 7. I thought I dictated as many points as I could today. It's not always possible because you're playing against top tennis players and he's got a lot of firepower as well, but I did a good job of that."
In front of a noisy crowd on Court Suzanne Lenglen, the second biggest court at Roland Garros, a brilliant backhand pass in the third game gave Murray the first break, only for the Scot to hand it straight back in the following game as Verdasco levelled at 2-2.
The Wimbledon champion competed in almost every one of Verdasco's service games and, after failing to take one of two break points at 2-2, Murray forced an error from his opponent to lead 5-4 and then duly served out to take the opening set.
Murray was hitting flat, hard and with authority but when he failed to take advantage of a number of good chances to break Verdasco, it seemed as if it might come back to haunt him. A cunning low backhand slice pass helped to put him 6-5 up in the second set, however, and he held a long service game to double his lead.
When Murray then broke in the opening game of the third set, the match looked over but it says a lot about how confident Murray was feeling that even in the heat of the battle, he was able to show his belief in fair play.
Leading 4-2 - and having missed a number of break-point chances on the Verdasco serve - Murray 'framed' a return, allowing the Spaniard to reduce the deficit. The umpire, Pascal Maria, however, ordered a let to be played as the call, which was made in error, had come before Murray hit the ball. However, the Scot gave the point away.
It was a moment of generosity he might have regretted when Verdasco broke back for 4-4 but Murray played a superb tie-break to win it 7-3 and take his place in the last eight. "It was a great serve and I miss-hit the ball," Murray said. "It didn't go in. I gave him the point."
His next opponent, Monfils, was a straight-sets winner over Guillermo Garcia-Lopez of Spain, will present a significant challenge in front of his home crowd. "I think in [all] the grand slams [he's played], he's played his best tennis here by far," added Murray.
"He loves playing in front of a big crowd. He's a great athlete, maybe the best we have had in tennis. I'm sure there will be some fun rallies. There always are when I have played against him. We haven't played against each other for quite a while, so I'm looking forward to it."
On the day when the King of Spain, Juan Carlos, announced his intention to abdicate the throne, the Spanish king of Roland Garros, Rafael Nadal, showed yet again that he is not ready to let slip his crown. The world No.1 looked free from a troublesome back injury as he crushed Serbia's Dejan Lajovic 6-1, 6-2, 6-1 to reach the last eight without losing a set.
Eight-time champion Nadal now plays compatriot David Ferrer after the fifth seed saw off Kevin Anderson 6-3, 6-3, 6-7, 6-1. Today, it is the turn of Novak Djokovic as he plays Canadian Milos Raonic, while Tomas Berdych takes on Roger Federer's conqueror, Ernests Gulbis.