Victoria Azarenka and Angelique Kerber were big-name casualties in the first round of the French Open on day three, but defending champion Serena Williams eased through.
Azarenka has looked capable of adding to her two grand slam titles this year, but the fifth seed will not be achieving that feat at Roland Garros after retiring with a knee injury when trailing 3-6 7-6 (8-6) 0-4 against Karin Knapp.
Kerber won her first grand slam title at the Australian Open in January, but fell at the first hurdle in Paris when Kiki Bertens beat the third seed 6-2 3-6 6-3 on Court Philippe Chatrier.
Top seed Williams strolled into round two with a 6-2 6-0 demolition of Magdalena Rybarikova, who was hampered by injury, in only 44 minutes.
DEJA VU FOR CROCKED AZARENKA
Azarenka was beaten by Knapp at Roland Garros in 2007 and suffered more disappointment when she limped out of her first match against the unseeded Italian since that meeting nine years ago.
Former world number one Azarenka, a winner of three titles in 2016, revealed the pain became too much for her to bear in the deciding set.
The Belarusian said: "Heading into the match today I was feeling fine. I was ready to play. But I started to feel a sharp pain in my right knee. I've had an injury there before, a while ago, but it hasn't been a problem until today.
"At first it was on and off and I was able to win the tie-break, but then it got worse as the match went on, and unfortunately there was nothing I could do."
BERTENS ON A ROLL
Bertens headed to Paris on the back of a tournament victory in Nuremburg last week and Kerber felt the force of her impressive form.
The world number 58 from the Netherlands was leading the Australian Open champion in the deciding set at the Miami Open in March when she retired due to illness, but she was not to be denied this time around.
Kerber has now lost her last three matches and stated after her early exit: "I was trying it. It was not my day." Bertens will face Camila Giorgi in round two.
SCHIAVONE NOT FINISHED YET
The 2010 French Open champion Francesca Schiavone was unable to pull off an upset against Kristina Mladenovic, but the Italian was in for a shock of her own when the crowd were informed of her retirement following her 6-2 6-4 defeat.
That was news to the 35-year-old, who let it be known in no uncertain terms that her career had not come to an end in her media conference.
She said: "No, no, no. So Roland Garros announced my retirement, but I didn't. So you can stand up all of you and go back to work in the office because I didn't say that. I will announce when I will want to stop. It was not the last one for me."
SERENA NOT CONCERNED BY FLEETING ENCOUNTER
The first-round match of top seed and favourite Williams was over in the blink of an eye, but the legendary American had no problem with such a short time on court as she turns her attention to facing Teliana Pereira in round two.
She said frankly: "It was a little short for me. But I think in my career if I don't have it by now I need to look into something different."