Paris - Former world number one Venus Williams suffered a shock defeat by Chinese player Wang Qiang in the French Open first round on Sunday.
The 37-year-old ninth seed was well short of her best as Wang claimed a 6-4, 7-5 victory and gained a measure of revenge for her first-round loss to Venus at Roland Garros last year.
The seven-time Grand Slam champion has now lost both her matches at major tournaments this year, having reached the Australian Open and Wimbledon finals in 2017.
Wang, the world number 91, has never made the third round of a Slam, and will face Petra Martic of Croatia for a place in the last 32 after the biggest win of her career.
World number nine Venus will now turn her attention to playing the doubles tournament with her sister Serena, who is competing in a Grand Slam event for the first time since last year's Australian Open after giving birth to her daughter.
Results from day one of the French Open at Roland Garros on Sunday (x denotes seeding):
Martin Klizan (SVK) bt Laslo Djere (SRB) 7-6 (8/6), 4-6, 7-6 (8/6), 6-1
Gael Monfils (FRA x32) bt Elliot Benchetrit (FRA) 3-6, 6-1, 6-2, 6-1
Pablo Carreno-Busta (ESP x10) bt Jozef Kovalk (SVK) 4-6, 6-1, 7-5, 7-6 (7/5)
Jared Donaldson (USA) bt Nicols Jarry (CHI) 6-3, 4-6, 3-6, 6-3, 6-4
Grigor Dimitrov (BUL x4) bt Mohamed Safwat (EGY) 6-1, 6-4, 7-6 (7/1)
Kei Nishikori (JPN x19) bt Maxime Janvier (FRA) 7-6 (7/0), 6-4, 6-3
Damir Dzumhur (BIH x26) bt Denis Kudla (USA) 6-4, 6-2, 6-2
Radu Albot (MDA) bt Gregoire Barrere (FRA) 4-6, 0-6, 7-5, 6-1, 6-2
Ekaterina Makarova (RUS) bt Zhneg Saisai (CHN) 6-4, 6-1
Barbora Strycova (CZE x26) bt Kurumi Nara (JPN) 1-6, 6-3, 6-4
Jennifer Brady (USA) bt Amandine Hesse (FRA) 6-1, 6-1
Petra Martic (CRO) bt Wang Yafan (CHN) 6-2, 6-3
Elina Svitolina (UKR x4) bt Ajla Tomljanovic (AUS) 7-5, 6-3
Anett Kontaveit (EST x25) bt Madison Brengle (USA) 6-1, 4-6, 6-2
Sloane Stephens (USA x10) bt Arantxa Rus (NED) 6-2, 6-0
Alize Cornet (FRA x32) bt Sara Errani (ITA) 2-6, 6-2, 6-3