PARIS (Reuters) - Highlights of the eighth day at the French Open, the second Grand Slam of the year, on Sunday (times GMT):
Serena Williams saw another chance to claim a record-equalling 24th Grand Slam singles title pass her by as the 39-year-old American was outplayed by Kazakhstan's Elena Rybakina in the fourth round.
Roger Federer also bowed out although not on the court but by withdrawing, the day after reaching the last 16, as a precautionary measure to protect his knees.
Shortly after Victoria Azarenka, one of the biggest potential threats to Williams in the bottom half, had lost 5-7 6-3 6-2 by Russia's Anastasia Pavlyuchenkova, Williams walked on to play the 21-year-old Rybakina for the first time.
But the American was outplayed, losing 6-3 7-5 to a player contesting her first Grand Slam last 16 match.
Marketa Vondrousova, the 2019 runner-up, lost to Spain's Paula Badosa 6-4 3-6 6-2, while Tamara Zidansek of Slovenia completed an unlikely lower half of the draw by beating Romanian Sorana Cirstea.
World number two ccontinued to make a mockery of his apparent dislike for clay as he dismantled Chile's 22nd seed Cristian Garin 6-2 6-1 7-5 to set up a quarter-final clash with fifth seed Stefanos Tsitsipas.
Russian Medvedev has conceded only one set so far. Tsitsipas outclassed Pablo Carreno Busta.
Sixth seed Alexander Zverev had far too much power for Kei Nishikori, thrashing the Japanese player 6-4 6-1 6-1 to reach his third Roland Garros quarter-final where he will face Spain's surprise package Alejandro Davidovich Fokina.
2110 ZVEREV THRASHES NISHIKORI TO REACH LAST EIGHT
Alexander Zverev swept past Kei Nishikori 6-4 6-1 6-1 to reach the quarter-finals for the third time in an evening session match that turned into an anti-climax.
The sixth seed will face Spanish youngster Alejandro Davidovich Fokina next.
1900 DAVIDOVICH FOKINA BATTLES PAST DELBONIS
Spanish youngster Alejandro Davidovich Fokina booked a place in a Grand Slam quarter-final for the first time in his career with a hard-fought 6-4 6-4 4-6 6-4 victory over Argentina's Federico Delbonis.
1715 SERENA WILLIAMS OUSTED BY RYBAKINA IN STRAIGHT SETS
Kazakhstan's Elena Rybakina dismantled seventh seed Serena Williams 6-3 7-5 to move into the quarter-finals of a Grand Slam for the first time in her career.
Williams, 39, was broken five times and made 19 unforced errors while Rybakina fired 21 winners.
1525 MEDVEDEV SETS UP QUARTER-FINAL CLASH WITH TSITSIPAS
Russian second seed Daniil Medvedev beat Chile's 22nd seed Cristian Garin 6-2 6-1 7-5 to set up a mouth-watering quarter-final clash with Stefanos Tsitsipas.
Medvedev, who had never won a match at the French Open before this year, now has a 4-4 record at Roland Garros.
1455 TSITSIPAS CRUISES INTO QUARTERS WITH STRAIGHT SETS WIN
Greek fifth seed Stefanos Tsitsipas gave a near flawless performance to beat 12th seed Pablo Carreno Busta 6-3 6-2 7-5 and reach the last eight, smashing 41 winners and converting five break points.
1425 FEDERER WITHDRAWS FROM FRENCH OPEN
Roger Federer withdrew from the French Open on Sunday, a day after winning a tough third-round match, opting to save himself for the grasscourt season.
"After two knee operations and more than a year of rehabilitation, it's important that I listen to my body and not rush back into competition," the 39-year-old Swiss said.
1410 AZARENKA SLAMS ORGANISERS AS MEN'S MATCHES FAVOURED FOR NIGHT SESSIONS
Former world number one Victoria Azarenka has questioned the tournament organisers over the scheduling of matches, with six of the seven night sessions so far this year featuring only men's matches.
"What concerns me is when somebody from the French federation is continuously trying to say there's equality and only pointing to prize money, which is true," she said. "Everything else, I wouldn't even agree a little with that."
1400 SWIATEK & MATTEK-SANDS SEAL COMEBACK WIN
Reigning singles champion Iga Swiatek and Bethanie Mattek-Sands saved an incredible seven match points before overcoming top seeds Elise Mertens and Hsieh Su-wei 5-7 6-4 7-5 in their women's doubles third round match.
1255 BADOSA BATTLES PAST VONDROUSOVA
Spain's Paula Badosa won her second straight three-set battle at the French Open to beat Czech 20th seed Marketa Vondrousova 6-4 3-6 6-2 and reach the last eight at a Grand Slam for the first time in her career.
Badosa, the number 33 seed, will face Slovenia's Tamara Zidansek in the quarter-finals.
1220 AZARENKA UPSET BY PAVLYUCHENKOVA
Russia's Anastasia Pavlyuchenkova battled hard to beat 15th seed Victoria Azarenka 5-7 6-3 6-2 and reach the French Open quarter-finals for the first time in 10 years.
Pavlyuchenkova struck 45 winners and was helped by Azarenka making 30 unforced errors.
1043 ZIDANSEK REACHES FIRST GRAND SLAM QUARTER-FINAL
Tamara Zidansek came through a tight opening set before dominating Romanian Sorana Cirstea to seal a 7-6(4) 6-1 win that made her the first woman from Slovenia to reach the singles quarter-finals of a Grand Slam.
0908 PLAY UNDER WAY
Play began in sunny conditions at Roland Garros, with the temperature at around 17 degrees Celsius.
Victoria Azarenka takes on Anastasia Pavlyuchenkova on Court Philippe Chatrier from 1000 GMT, before matches involving Stefanos Tsitsipas, Serena Williams and Alexander Zverev on the main showcourt.
(Reporting by Simon Jennings, Shrivathsa Sridhar Hardik Vyas and Rohith Nair in Bengaluru; editing by Clare Fallon and Ken Ferris)