Andrey Rublev blew his top along with his French Open hopes to become the biggest men's casualty so far on another rain-drenched day at Roland Garros.

But while the volatile Russian sixth seed was being no saint under the roof of Court Suzanne Lenglen on his way to being knocked out by Italian giant-slayer Matteo Arnaldi 7-6 (8-6), 6-2, 6-4, Jannik Sinner moved sweetly into the last 16 on Friday.

Rublev's hot-headed side came to the fore again in the second set, after he was already frustrated at spurning a set point in the first, when he got embroiled in an argument with umpire Lazemar Engzell over a disputed line call.

It got worse when he then dropped serve and furiously smashed his racquet into the clay, ranted towards his players' box and, at the subsequent changeover, left a dent in the courtside bench by booting it.

By the third set, with blood boiling, he turned his wrath on himself, belting his own knee with his racquet.

And he continued berating himself later, saying: "Completely disappointed with myself, the way I behaved, the way I performed, and I don't remember behaving worse on a slam ever.

"I think it was first time I ever behaved that bad.

"It's not about concentration, it's because the way I behave I put myself completely down, and I give Matteo wings to fly, and he was flying in the third set. It was too late to do something."

Rublev's most unwelcome claim to fame is playing 10 grand slam quarterfinals and losing them all, but he didn't even get that far this time as 23-year-old Arnaldi, who had already knocked out the French 29th seed Arthur Fils in the first round, enjoyed his biggest win.

"It's incredible, I mean I think I played the best tennis for sure in my life I would say," said Arnaldi, who will play either Greece's Stefanos Tsitsipas or China's Zhang Zhizhen in the last 16.

World number two Sinner looks as if he will take some beating after a ruthless take-down of Russian Pavel Kotov 6-4, 6-4, 6-4.

Dressed for the weather with a long-sleeved undershirt, Italy's Australian Open champion faced just one break point as he largely dominated the world number 56 to set up a last-16 date with either Austrian Sebastian Ofner or France's Corentin Moutet.

Iga Swiatek didn't dare celebrate her 23rd birthday until she had done her day job properly.

But the world number one broke into beaming smiles once she had demolished Marie Bouzkova, eased into the last 16 of the French Open and had the Roland Garros crowd serenade her.

The champion had just about survived in the previous round when she was match point down to Naomi Osaka, but she made light work of beating the Czech Bouzkova 6-4, 6-2 before the chorus of "Happy Birthday" resounded around Court Philippe-Chatrier.

Swiatek was worried the fickle French crowd might have turned on her after she reproached them gently following the Osaka match for their behaviour, but she need not have been concerned as they embraced her warmly following her 15th unbeaten match on clay, having also won titles in Madrid and Rome this month.

"I was waiting until after the match to feel that I have a birthday because I knew that I need to focus on my work because if I would lose, it would be a total disaster," Swiatek said.

"So I'm happy that I won — and I kind of gave myself a present.

"For sure playing on your birthday, it's not so comfortable because it's eight o'clock and I have four hours left to celebrate. But that's the work that we have to do — we can't complain."

She made it 17 wins in a row at Roland Garros with considerable efficiency, hammering 18 winners in the opening set alone before Bouzkova tested her in a brief second-set fightback before succumbing in one hour, 33 minutes.

The champ, who will next face Russia's world number 41 Anastasia Potapova, reckoned she felt "good physically" after her exertions against Osaka. 

"I don't feel like the match stayed with me, but we'll see at the end of the tournament," she said.

Dayana Yastremska, the Ukrainian who put paid to the hopes of Australian comeback luminary Ajla Tomljanovic, met her match after giving Coco Gauff a test.