PARIS - Iga Swiatek stayed cool in sweltering conditions while Novak Djokovic was given a stern test before reaching the third round of the French Open, but world number ​two Elena Rybakina was unable to avoid an early exit on Wednesday.

Rome champion Elina Svitolina continued to mark herself out as a genuine title contender with a 6-0 6-4 victory ‌over Kaitlin Quevedo on Court Philippe Chatrier, before fellow Ukrainian and Madrid winner Marta Kostyuk beat Katie Volynets 6-7(4) 6-3 6-3.

Yuliia Starodubtseva of Ukraine fought past Rybakina 3-6 6-1 7-6(10-4) for a first top-five win. Fresh from claiming her second Grand Slam at the Australian Open in January, Roland Garros second seed Rybakina was a shadow of ​her usually dominant self as she made 71 unforced errors in the clash with Starodubtseva to bow out tamely.

"I feel like if you're trying to beat one of the best, you ​have to think that you can," Starodubtseva told reporters.

"I was trying to go into this match with this mindset, try not to give too much respect, ⁠even though she's a great player and someone you can look up to."

Russian eighth seed Mirra Andreeva seemed to be joining Rybakina through the exit door but she regained her composure to down Spain's ​Marina Bassols Ribera 3-6 6-1 6-1.

Jasmine Paolini, the 2024 runner-up, was beaten 3-6 6-4 6-3 by Argentina's Solana Sierra.

Swiatek is another player trying to rediscover her belief at the French Open after a lackluster few months ​but the four-times winner was plagued by 38 unforced errors but still had too much quality as saw off Czech Sara Bejlek 6-2 6-3.

"It was a tricky match in terms of the rhythm, because Sara plays differently than most of the players," Swiatek said.

"I'm happy with the way I adjusted and how I was making decisions, because sometimes it wasn't obvious when to attack and stay back. In the end I felt pretty good."

Three-times champion Djokovic then overcame stiff resistance from ​local favorite Valentin Royer to seal a 6-3 6-2 6-7(7) 6-3 victory, as the Serb stayed on track for a standalone 25th Grand Slam title at the age of 39.

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"I think Valentin deserves a big ​round of applause for his performance today. I hope I won't play any more French players for the rest of the tournament," said Djokovic, who opened his campaign against Giovanni Mpetshi Perricard.

While that clash against Frenchman Perricard was ‌played in the ⁠cool conditions of the evening, Djokovic was made to sweat as Paris continued to reel under the heatwave that has tested players.

"The feelings on the court are different when you win," added Djokovic.

"But it was a tough match in difficult conditions."

While Djokovic was cheered on from the stands by his coaching team that included new addition Viktor Troicki, it was a different story for Alejandro Davidovich Fokina.

Abrupt exit

The Spaniard found himself without a coach at the Grand Slam as his mentor Mariano Puerta abruptly left the venue after sending Davidovich Fokina a text message and flew to Miami, leaving him to fend for himself in his clash with Argentine ​Thiago Agustin Tirante.

"After the match against Damir Dzumhur, ​we had lunch and after that, I went ⁠to cool down. He said he was feeling bad, he was going to the hotel," Davidovich Fokina explained after his four-set win over Tirante.

"In the afternoon ... he texted me a message (saying) he'll not continue ... he didn't say nothing to anybody, he just took the flight and flew to Miami."

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Alexander Zverev took another step in his quest for a maiden Grand Slam title as ​he dismantled Czech Tomas Machac 6-4 6-2 6-2 in the evening session.

Zverev's fellow Tokyo Olympics gold medallist Belinda Bencic earlier breezed past American Caty McNally 6-4 6-0.