World number one Angelique Kerber became the first number one women’s seed to lose in the opening round of the French Open.
The 29-year-old German went down 6-2 6-2 to Russia’s Ekaterina Makarova on the Philippe Chatrier Court, in a match which lasted one hour and 22 minutes.
Despite regaining the number one status earlier this year, Kerber has struggled for form recently, losing early in Madrid and Rome.
Her latest defeat could open the door for Simona Halep or Karolina Pliskova to claim the world number one ranking, if they reach the latter stages in Paris.
Makarova dominates from start to finish
Makarova, the world number 40, was always going to provide a stern test for the top seed, and from start to finish it was the Russian who looked like the higher ranked player.
After racing into a 5-1 lead, courtesy of a double break, Makarova closed out the opening set in 33 minutes.
The second set followed a similar pattern, with Kerber losing her serve twice to fall 0-3 behind.
The next four games went against serve before the Russian finally closed out the contest.
Kerber finished the match with 25 unforced errors, after converting just two out of 16 break points.
Wins for Williams and Kvitova
Elsewhere on the opening day, Venus Williams battled past China's Wang Qiang with a 6-4 7-6 (7-3) victory.
Petra Kvitova was also triumphant in her first match for six months, after she was stabbed during an attack at her home back in December.
The 27-year-old Czech beat American Julia Boserup 6-3 6-2 in the first match of the day on the Philippe Chatrier Court.
Robredo too strong for Evans
In the men’s draw, Britain’s Dan Evans was defeated by 35-year-old Spaniard Tommy Robredo.
After winning the opening set, Evans went down 5-7 6-4 6-3 6-1 in sweltering conditions in the French capital.
Eighth seed Dominic Thiem was victorious with a comfortable 6-4 6-0 6-2 over Bernard Tomic.
There were also wins for 11th seed Grigor Dimitrov and home favourite Lucas Pouille.