Johanna Konta’s maiden French Open semi-final has been pushed back to Friday after rain washed out Wednesday’s play in Paris.
The British number one, 28, was set to meet Czech teenager Marketa Vondrousova in the last four on Thursday.
But downpours on Wednesday meant the remaining women’s singles quarter-finals could not be played.
They will take place on Thursday instead, with both semi-finals now on Friday.
The weather in Paris is forecast to be brighter on Thursday with a chance of a brief shower in the afternoon.
However, more rain is forecast for Friday which has led tournament director Guy Forget to “study worst-case scenarios”.
One of the women’s semi-finals could be moved to Court Simonne Mathieu if a decision is made to use Roland Garros’ third show court alongside Chatrier and Lenglen in a bid to complete the matches.
Forget added it was possible the women’s final could be pushed back to Sunday, with the men’s final switching to Monday.
“It’s not what we hope, but if we have no other choice, then that’s what we will do,” he said.
Konta, seeded 26th, is bidding to become the first British woman to reach the French Open final since Sue Barker in 1976.
Romania’s defending champion Simona Halep was due to play American teenager Amanda Anisimova in their quarter-final on Wednesday, while Australian eighth seed Ashleigh Barty was scheduled to meet American 14th seed Madison Keys.
The rain also saw the two remaining men’s quarter-finals cancelled, meaning all four matches will be played from 11:00 BST on Thursday.
World number one Novak Djokovic plays German fifth seed Alexander Zverev, while Austrian fourth seed Dominic Thiem meets Russian 10th seed Karen Khachanov.
British pair Alfie Hewett and Gordon Reid are also set to begin their French Open wheelchair campaigns on Thursday, with the singles and doubles draws taking place later on Wednesday.
Hewett won the singles title in 2017, while Reid has twice won the doubles at Roland Garros.