World number one Naomi Osaka’s hopes of winning a third successive Grand Slam ended Saturday when she was knocked out of the French Open in the third round by unheralded Katerina Siniakova of the Czech Republic.

Japanese top seed Osaka, the reigning US and Australian Open champion, crashed to a 6-4, 6-2 defeat to the 42nd-ranked Czech.

Osaka’s defeat left just four of the women’s top 10 seeds left in the tournament including three-time winner Serena Williams and defending champion Simona Halep.

Osaka was undone by a shocking 38 unforced errors as she finally ran out of luck in Paris having had to come back from a set down in her first two matches. Osaka dropped the first set for the 3rd successive match at the tournament, squandering seven break points in all.

Siniakova made her pay, breaking for 5-4 and taking the opener when Osaka sent back her 16th unforced error of the set. The Czech kept up the pressure on the misfiring top seed, breaking for a 3-2 lead in the second set.

Siniakova backed it up with another break for 5-2 off Osaka’s third double fault of the match.

Victory was hers on Court Suzanne Lenglen when Osaka unleashed another misguided forehand.

The Czech goes on to face Madison Keys of the United States for a place in the quarter-finals in what will be her first appearance in the last 16 of the majors.

Osaka had never looked convincing in Paris. She was two points away from defeat in the first round against Anna Karolina Schmiedlova and came back from a set and break down to see off Victoria Azarenka in round two.

There were no such problems for men’s world number one Novak Djokovic who eased into the last 16, stepping up his bid to hold all four Grand Slam titles simultaneously for the second time.

The Serbian saw off unseeded Italian Salvatore Caruso 6-3, 6-3, 6-2 to set up a fourth-round tie with either Germany’s Jan-Lennard Struff or Croatian 13th seed Borna Coric. It is the 10th successive year the top seed has reached the second week -- and 13th in total -- as he looks for a second French Open title after sealing his first ‘Djoko’ Slam in Paris in 2016.

Alexander Zverev needed another five-setter to reach the fourth round, defeating Serbia’s Dusan Lajovic 6-4, 6-2, 4-6, 1-6, 6-2.

Zverev will face Italy’s Fabio Fognini for a place in the last-eight.

Fognini needed four sets to defeat Spanish 18th seed Roberto Bautista Agut 7-6 (7/5), 6-4, 4-6, 6-1.

Crowd favourite Tsitsipas became the first Greek player in 83 years to reach the second week at Roland Garros as he survived a scare against Filip Krajinovic.

The sixth seed led by two sets when the match was suspended at 5-5 in the third due to darkness just before 10:00pm on Friday.

On the resumption Saturday, Tsitsipas lost the set in a tie-break but sealed a 7-5, 6-3, 6-7 (5/7), 7-6 (8/6) success on Court Philippe Chatrier.

The 20-year-old will take on Stan Wawrinka for a place in his second Grand Slam quarter-final.

Wawrinka, the 2015 champion and a three-time major winner, recorded his 500th match win with a 7-6 (7/5), 7-6 (7/4), 7-6 (10/8) win over Grigor Dimitrov.

Meanwhile, last year’s runner-up Dominic Thiem reached the French Open last 16 for the fourth straight year with a four-set win over Uruguayan Pablo Cuevas. The Austrian fourth seed dropped the second set to world number 47 Cuevas, but did enough to win 6-3, 4-6, 6-2, 7-5 and set up a fourth-round clash with French favourite Gael Monfils.

Juan Martin del Potro eased past Australian Jordan Thompson and into the second week with a comprehensive 6-4, 6-4, 6-0 victory.

Del Potro will take on Russian 10th seed Karen Khachanov for a place in the last eight.

Agence France-Presse