Although the temperature is expected to drop on Sunday, the pressure will mount as Roland Garros enters its second week with thinned fields and the ultimate prize almost in sight.
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The week-long heatwave helped wreak havoc in the men's draw. After the elimination of a wilting Jannik Sinner and a fading Novak Djokovic in five-setters on consecutive evenings, not a single Grand Slam singles winner is still standing.
The throne is vacant ahead of next Sunday's men's final when a new sun-proof king of clay will be crowned.
For the two men who have reached finals at majors, three-time losers Casper Ruud and Alexander Zverev, the trick will be to focus on Sunday's opponent.
"It's such an open tournament, which is kind of refreshing, I guess, for everyone, and to see that there will be a new Slam champion in about a week or so. I think every player is aware of it," said Ruud in the early hours of Saturday morning after coming from two sets down as the evening cooled to beat American Tommy Paul.
"Obviously Novak and Jannik was one of the two highest favourites," the Norwegian added.
"It will be interesting to see where we are in a week's time. I'm going to try to use the experiences that I've had of reaching far in Slams to my advantage and see where that takes me, but you focus one match at a time."
Ruud's next match is against Djokovic's teenage conqueror Joao Fonseca, who the 15th seed called a "special talent".
For the 19-year-old Brazilian, this is uncharted territory.
"That was my first fourth round in my career," he said after his win.
"I'm just thinking about my next match," he insisted. While too discreet to name himself a challenger, he nonetheless hinted he might be dreaming of bigger things.
"Of course, Jannik and Djokovic out, there's more chances for the guys that are more time on tour, like Sascha (Zverev), Casper, or whatever."
Zverev, at No 2, the highest remaining men's seed, faces Jesper de Jong, who has played 21 sets in his Roland Garros campaign, more than anyone else.
He is also the only remaining player to have lost a match. The Dutchman was eliminated in the final round of qualifying but inherited a seeded slot in the main draw as a lucky loser when injured French No 1 Arthur Fils withdrew.
De Jong had never made it past the second round at a major before, but said the draw had never been kind, pairing him with top players such as German Zverev.
After the Dutchman fought back to beat 13th seed Karen Khachanov in the third round, he said his fifth-set "toilet break, that was the key".
Now he faces Zverev.
"It's better in the fourth round than in the second round," he said.
In a tournament where youth has thrived, Fonseca is just one of three 19-year-olds in action.
'RECHARGING MY BATTERIES'
Spanish phenom Rafael Jodar, like Fonseca already a top-30 player, faces unseeded 34-year-old compatriot Pablo Carreno Busta.
Mirra Andreeva, the women's eighth seed takes on Swiss veteran Jil Teichmann who, at 28, is seemingly rejuvenated after a long break "recharging my batteries".
The women's draw has no shortage of players who know what it is to be crowned queen, despite the exit of reigning champion Coco Gauff on Saturday.
One, Iga Swiatek is in action on Sunday, her 25th birthday. The Polish third seed has won Wimbledon and the US Open once each and Roland Garros four times, the last three in a row until she was deposed by Aryna Sabalenka in last year's semifinals.
She faces 15th-seeded Ukrainian Marta Kostyuk.
The top Ukrainian, seventh-seeded Elina Svitolina will be attempting to match her best Roland Garros performance and reach a sixth quarterfinal. She faces a second Swiss veteran, 11th seed Belinda Bencic who at 29 is playing in the fourth round at Roland Garros for the first time.