Novak Djokovic placed ice packs around his neck and on top of his head during changeovers to keep cool amid the Paris heat wave at the French Open on Wednesday.

Djokovic continued his latest tilt at a record-breaking 25th Grand Slam title with a four-set victory on Wednesday to reach the third round, but suggested matches should be pushed back later in the day to combat the heat wave broiling the players at Roland Garros.

Just as he did in his opening match, the 39-year-old saw off a home player, this time moving past world No 74 Valentin Royer 6-3, 6-2, 6-7 (7), 6-3 under the blazing sun on Court Philippe Chatrier.

"Obviously the feelings on the court are different when you win," Djokovic said.

"It was a match in very difficult (weather) conditions."

Speaking to reporters later, Djokovic suggested matches be put back to avoid playing during the hottest part of the day, as temperatures in the French capital continue to reach the mid-30s Celsius.

"Honestly, with Grand Slams it shouldn't be an issue, generally, because we have so many courts. We have lights. You know, there's no issue. You have big courts. You can play the matches. You can reschedule them on some other courts and have still the crowd in the stadium and everything," he said.

"For example, Umag in Croatia, where matches are starting later in the afternoon, you know, 5 pm or something, they play until deep into the night.

"Yeah, is it ideal to go past midnight? No, it's not. But if you have, you know, certain days that you have extreme heat and conditions, then maybe that's something to consider."

On center court, Djokovic confidently navigated his way into a two-set lead against Royer.

The Frenchman, born some five kilometers from Roland Garros, gave the local fans cause to cheer when he twice canceled out Djokovic breaks to level at 3-3 and 4-4 in the third set.

He then brought center court to its feet as he recovered from 3-0 down in the tie-break to force a fourth set.

Djokovic opened the frame with a battling hold of serve, as he seemed to flag in the late afternoon sun with the match fast approaching the three-hour mark.

But, the three-time French Open champion dug deep to stay in the fight, and one stretching forehand from wide out beyond the net post brought a smile to his lips as Royer disbelievingly watched it rip off the clay just inside his baseline.

That moment of brilliance was all Djokovic needed to revitalize himself as he broke for a 3-1 lead in the very next game, before serving out his spot among the last 32.

"I think Valentin merits a big round of applause for his performance today," Djokovic said.

"I hope I won't play any more French players for the rest of the tournament," he added with a wry laugh.

Djokovic improved to 14-0 in his career against Frenchmen at Roland Garros and reached the third round in Paris for a 21st straight year. He raised the Coupe des Mousquetaires trophy in 2016, 2021 and 2023.

One pair of Djokovic fans inside the main stadium held up a sign with a goat on it — for "Greatest of All Time" — that read "39 is the new 29".

Generational clash

Indeed, Djokovic will next face 19-year-old Brazilian Joao Fonseca, who was born more than a year after the veteran's debut at Roland Garros.

If Djokovic has got his wish of not immediately facing a French player again, there will still doubtless be a huge, vocal group of supporters in the crowd backing his opponent during Friday's third-round match.

Wherever Fonseca plays he attracts masses of Brazilian fans, and it was no different on Court 14 on Wednesday as plenty of his compatriots were on hand to sing him over the line in five sets against Croatian 20-year-old Dino Prizmic — the player who eliminated Djokovic from the Italian Open earlier in May.

Fonseca, for the first time in his professional career, came back from two sets to love down to win 3-6, 4-6, 6-3, 6-1, 6-2 in a meeting between two rising stars of the tour that more than lived up to its billing.

"Fonseca has been praised so much in the last couple of years, you know, I think his potential and quality as a tennis player is obvious, no doubt about it. He's got big Brazilian support anywhere he goes. I think he's a big-stage player. He really loves the occasion," Djokovic said of the 28th seed.

It will be Fonseca's first ever meeting with the 24-time Grand Slam winner.

Ukraine gets three wins

Elena Rybakina, this year's Australian Open winner, was beaten by Ukrainian opponent Yuliia Starodubtseva 3-6, 6-1, 7-6 (4).

Starodubtseva will face China's Wang Xiyu for a place in the last 16.

The 26th seeded American Hailey Baptiste was forced to retire while facing a set point against Wang after landing awkwardly on her left leg.

Also advancing were Ukrainians Elina Svitolina and Marta Kostyuk, both of whom are coming off trophies at the Madrid Open and Italian Open, respectively.

The seventh-seeded Svitolina beat Kaitlin Quevedo 6-0, 6-4 to extend her winning streak to eight matches. The 15th-seeded Kostyuk beat Katie Volynets 6-7 (4), 6-3, 6-3 to extend her winning streak to 13 matches.

"I'm most pleased that I didn't cramp to death or didn't pass out during this match," Kostyuk said after her match, which lasted nearly three hours. "It was not easy for everyone."

Four-time champion Iga Swiatek improved her career record at Roland Garros to 42-3 by eliminating 35th-ranked Sara Bejlek 6-2, 6-3.