(Reuters) - Highlights of the seventh day at the French Open, the second Grand Slam tournament of the year, on Saturday (all times GMT):

1820 KENIN UPSETS SERENA

Serena Williams suffered a surprise 6-2 7-5 defeat by compatriot Sofia Kenin in the third round of the French Open.

Williams, a 23-times Grand Slam singles champion, has finished runner-up at two of the last three majors but has been unable to add to her tally since returning to the sport following the birth of her first child in 2017.

Kenin, 20, who reached the last 16 at Roland Garros for the first time, will now face Australian eighth seed Ashleigh Barty.

1700 DEL POTRO RACES INTO LAST-16

Argentine Juan Martin del Potro struck 38 winners and won the last seven games to beat Australian Jordan Thompson 6-4 6-4 6-0 in a ruthless display.

Del Potro, seeded eighth, will meet Russian Karen Khachanov for a place in the quarter-finals.

1655 THIEM OVERCOMES CUEVAS TO SET UP MONFILS CLASH

Fourth seed Dominic Thiem struggled to control his groundstrokes in the second set but recovered well to beat Uruguayan veteran Pablo Cuevas 6-3 4-6 6-2 7-5.

Thiem, who finished runner-up to Rafael Nadal last year, will next face Gael Monfils after he eased past fellow Frenchman

Antoine Hoang 6-3 6-2 6-3.

1410 DJOKOVIC CRUISES INTO LAST 16

Men's world number one Novak Djokovic eased past Italian qualifier Salvatore Caruso 6-3 6-3 6-2 to book his 13th appearance in the French Open fourth round.

1400 SINIAKOVA DUMPS OUT WORLD NO.1 OSAKA

Women's world number one Naomi Osaka was knocked out in the French Open third round by Czech Katerina Siniakova 6-4 6-2, ending her quest for a third successive Grand Slam crown.

With Osaka's defeat, five of the top six women's seeds are now out of the tournament.

It is the first time Siniakova has reached the fourth round of a Grand Slam in the singles.

1230 ZVEREV OUTLASTS LAJOVIC IN ANOTHER FIVE-SETTER

Fifth seed Alexander Zverev survived his second five-setter of the week to reach the fourth round for a second consecutive year, beating Serbia's Dusan Lajovic 6-4 6-2 4-6 1-6 6-2.

The German hotshot will next face Monte Carlo champion Fabio Fognini, who overcame Spain's Roberto Bautista Agut 7-6(5) 6-4 4-6 6-1.

1135 TSITSIPAS MAKES GREEK HISTORY

Sixth seed Stefanos Tsitsipas became the first Greek player to reach the Roland Garros fourth round since Lazaros Stalios in 1936, beating Serbia's Filip Krajinovic 7-5 6-3 6-7(5) 7-6(6).

Tsitsipas is one of the contenders for the title in Paris after finishing runner-up to Novak Djokovic in Madrid and reaching the semi-finals in Rome last month.

1005 HALEP SENDS TSURENKO PACKING

Defending champion Simona Halep eased past Ukrainian Lesia Tsurenko 6-2 6-1 to book a place in the last-16.

After being stretched in three-setters in her two previous rounds, Halep was pleased with a confidence-boosting victory heading into the second week of the tournament.

"I had in my head that I have to stay very strong, to play more aggressive, to stay closer to the baseline, which I did, and when I have the chance, to open the court," the 27-year-old Romanian said.

"So I think today was a better match. I played better. And I felt better on court."

(Reporting by Hardik Vyas in Bengaluru; Editing by Hugh Lawson and Pritha Sarkar)