"It's awesome what she has accomplished here", Laver told a packed media conference on Monday at Roland Garros.
The loss snaps her 16-match win streak at major tournaments.
"If I was told I would only make the third round here, I would have thought they were lying, because I wouldn't expect to have gotten only to the third round", said Williams after her loss on Saturday.
Williams surely remains a top figure surrounding women's tennis, but the once untouchable powerhouse now finds herself blazing down a bumpy road.
Siniakova, 23, has two career singles titles as well as two Grand Slam doubles crowns, including Roland Garros in 2018 alongside Barbora Krejcikova. "I don't really care about it too much", said Anisimova, the words flying out of her mouth with the same sort of pace that tennis balls zoom off her racket. Djokovic can become the first man to reach the French Open quarterfinals 10 years in a row.
As Williams served for the championship at 6-5, the Czech broke her to force a tiebreak, which she raced through by a 7-2 score to send the match into a decider.
"Yeah, I played her here at the French Open a few years ago in a match I would love to forget", Barty said after beating Kenin.
A series of unforced errors enabled Siniakova, ranked 42nd in singles, to seize control and Osaka cut a disconsolate figure as she slumped to defeat before making a hasty departure from the court. As long as Keys keeps that number within reason, she's a legit threat to anybody in this field due to her ability to take the racket out of her opponents hands. "But I feel stronger on court", she went on to say.
Next up for Siniakova will be American Madison Keys, a 6-3, 6-7 (5-7), 6-4 victor over Russia's Anna Blinkova, with the victor of that contest to take on either Kenin or Barty in the quarterfinals. "I'm just so happy now". The other quarterfinal matchup on her half is No. 8 Ash Barty of Australia against No. 14 Madison Keys of the U.S.
"I'm definitely feeling short on matches, and just getting in the swing of things".
First win over a World No.1. "I can only control how I prepare, how I play, and ultimately how we go about my next match".
A string of high-profile exits leaves only defending champion Simona Halep (third seed) and last year's finalist Sloane Stephens (seventh seed) as higher-ranked women than Barty in the draw.
"After you have a big win, you put a little bit more pressure on yourself", Keys said.
Kenin was also extremely well rested heading into her match against Williams, who is a three-time French Open champion.