Rybakina had just broken for a 3-1 lead in the first set when the Brazilian 13th seed winced in pain and clutched her back after netting a backhand.

Haddad Maia called on the physio and kept wincing as her back was being manipulated courtside. After leaving court to receive further treatment she returned in an attempt to resume the match following a 10 minute interval.

However, the way she stiffly bent down to pick up her racket from her chair to resume the contest signalled that the match might soon be over.

She tearfully went through the motions for one more game, clutching her back after every point before shaking her head to confirm that she could no longer continue.

Less than a minute later, a distraught Haddad Maia clutched her eyes in an attempt to stop the tears rolling down her face.

After a quick exchange with her team in the players' box, the Brazilian shook her head to confirm she could no longer continue and gingerly walked up to Rybakina to share an embrace.

"It's never easy to finish a match like this and I hope it's nothing really serious," said Kazakh Rybakina, who will next face either two-time champion Petra Kvitova or last year's runner-up Ons Jabeur.

"It was really unlucky for Beatriz and I hope she gets better," added the third seed.

The abrupt ending denied Roland Garros semi-finalist Haddad Maia of a chance to notch up a hat-trick of wins over Rybakina and also ended her hopes of becoming the first Brazilian woman in 55 years to reach the last eight of the grasscourt major.