Serena Williams knocked out of French Open third round by Sofia Kenin

Scream and shout Katerina Siniakova faces Naomi Osaka on Saturday

Williams failed to recover from a woeful start against fellow American Kenin as the 20-year-old motored into the last 16 with a 6-2, 7-5 win, putting the former world number one's quest for a record-equalling 24th singles major on hold.

It was 37-year-old Serena's earliest exit at the Slams since a third round loss to Alize Cornet at Wimbledon in 2014.

Williams made her Grand Slam return from childbirth in Paris past year, reaching the fourth round before withdrawing minutes before a match with Maria Sharapova due to a pectoral injury.

The No. 1-ranked Osaka couldn't muster a comeback after falling way behind yet again at the French Open, losing 6-4, 6-2 in the third round to No. 42 Katerina Siniakova of the Czech Republic on Saturday.

Sofia Kenin, 20, looks in shock after winning her third round match of the French Open against all-time great Serena Williams. Though Serena is battling back from injury, it was Sofia's calm, persistent play that propelled her to victory, clenching the match in just two sets (6-2, 7-5).

With Osaka gone, five of the top six seeds are now out of the women's singles draw, leaving Halep as the sole survivor. No. 8 Ashleigh Barty awaits.

World No.1 Osaka had won 16 consecutive slam matches, taking in titles at the US Open and Australian Open and two victories in Paris. She could yet follow up the doubles title she won her a year ago with the singles crown.

"I would have expected to have gotten past the the third round".

Since losing to Karolina Pliskova in the Australian Open quarter-finals in January, Williams has played in only three tournaments - Indian Wells, Miami and Rome - and has withdrawn from all of them. Asked if those preparations might include a rare trip to a pre-Wimbledon grass-court tournament, she replied: 'I'm definitely feeling short on matches, and just getting in the swing of things. "And it was obvious, I think".

It was a disappointing tournament for Serena but she admitted that Kenin was playing unbelievably well on the day.

Williams couldn't control her shots, compiling 34 unforced errors, twice as many as Kenin's 17.

"I didn't care at that point", Kenin said.

Down a set and a break, 3-2, against aggressive and seemingly fearless player-in-waiting Sofia Kenin, Williams looked disconsolate during the changeover. "I did feel some stares there, but I tried not to overthink it and do what I needed to do and do what I do best".

Barty won almost 80 percent of points on her fantastic first serve, and broke Petkovic four times out of six break points. "I'll take the win over the hitting".