World number one and former champion Ashleigh Barty limped out of Roland Garros on Thursday, throwing the battle for the women's title wide open as Rafael Nadal prepared to celebrate his 35th birthday inside an empty stadium.

Top seed Barty, already suffering from a left hip injury, retired injured midway through the second set of her second-round match against Poland's 45th-ranked Magda Linette.

The Australian, who won the title on her last visit to Roland Garros in 2019, left the court for medical treatment after losing the first set 6-1.

She then called it quits at 2-2 in the second set on Court Philippe Chatrier.

"It's heartbreaking," Barty said. "It's a miracle I got past the first round."

"We did absolutely everything we could to give myself a chance. It sucks."

Champion style: 2020 winner Iga Swiatek has been hitting with Rafael Nadal at Roland Garros this year
Champion style: 2020 winner Iga Swiatek has been hitting with Rafael Nadal at Roland Garros this year AFP / Anne-Christine POUJOULAT

The 25-year-old's withdrawal leaves the tournament already without the world's top three-ranked women's players.

World number two Naomi Osaka pulled out following a media boycott, saying she has suffered "bouts of depression" for three years.

Third-ranked Simona Halep, the 2018 French Open winner, withdrew before the event with injury.

That leaves world number four Aryna Sabalenka as the top remaining player in the draw.

Linette goes on to face Ons Jabeur, the Tunisian 25th seed who eased past Australian wild card Astra Sharma 6-2, 6-4.

Fourth seed Sofia Kenin, the 2020 runner-up, saw off American compatriot Hailey Baptiste 7-5, 6-3.

Painful end for Ashleigh Barty
Painful end for Ashleigh Barty AFP / Anne-Christine POUJOULAT

Three-time quarter-finalist and fifth seed Elina Svitolina was similarly untroubled against Ann Li of the United States, winning 6-0, 6-4.

However, ninth seed Karolina Pliskova exited at the hands of 2018 runner-up Sloane Stephens as the 59th-ranked American won 7-5, 6-1.

World number three Nadal, bidding for a 14th French Open and record-setting 21st Grand Slam title, faces Richard Gasquet, a player he first met when they were 12 years old.

However, schedulers have handed the Spaniard the evening session, leaving his 35th birthday party celebrations a little flat as the match clashes with a 9pm Covid-19 curfew and a spectator ban.

Lifelong rivals: Rafael Nadal and Richard Gasquet at the 2018 French Open
Lifelong rivals: Rafael Nadal and Richard Gasquet at the 2018 French Open AFP / CHRISTOPHE SIMON

Gasquet won his first junior clash against Nadal at the Petits As tournament in France in 1999.

Sadly for him, that was as good as it would ever get.

On the ATP Tour, Nadal has monopolised their head-to-head and leads 16-0.

"I don't have many French Opens left to play so I want to make the most of it," said Gasquet who made his debut at the tournament back in 2002.

Gael Monfils' 6-0, 2-6, 6-4, 6-3 defeat by Mikel Ymer of Sweden means Gasquet would have to beat Nadal to avoid the hosts suffering their worst year in men's singles since 1968.

Roger Federer, also the winner of 20 Slams, renews his rivalry with Marin Cilic.

The Swiss star leads their head-to-head 9-1 with Cilic's only win coming in the semi-finals of the 2014 US Open when he went on to claim his only Grand Slam title.

Federer, the 2009 champion in Paris, made the second round with a straight sets win against Uzbek qualifier Denis Istomin.

It was just his second win in 2021 and first at a major since losing to Novak Djokovic in the 2020 Australian Open semi-finals.

Top seed and world number one Djokovic is also in a battle of the over 30s as he faces Uruguay's Pablo Cuevas.

Djokovic, the 2016 champion, is bidding to become the first man in more than half a century to win all four Slams more than once.

At the other end of the spectrum is 18-year-old Carlos Alcaraz who on Monday became the youngest player to win a match at Roland Garros since Djokovic in 2005.

If the Spaniard beats 28th seed Nikoloz Basilashvili, he will be the youngest man to reach the French Open last 32 since Andrei Medvedev in 1992.

Two Italian teens made it through with 18th seeded Jannik Sinner seeing off compatriot Gianluca Mager while highly-rated Lorenzo Musetti put out Japan's Yoshihito Nishioka.

Defending women's champion Iga Swiatek takes on Sweden's Rebecca Peterson.

Swiatek has hit with Nadal this week, a meeting which made her so nervous that the Pole prepared a list of helpful conversation starters should she get tongue-tied.