Jelena Ostapenko reached the Wimbledon semi-finals in 2018Dates: 28 May-11 June Venue: Roland Garros, ParisCoverage: Live text and radio commentaries of selected matches across BBC Radio 5 Sports Extra, the BBC Sport website and appFormer champion Jelena Ostapenko suffered a shock French Open second-round defeat by tournament debutant Peyton Stearns.
Latvian 17th seed Ostapenko, the winner at Roland Garros in 2017, lost 6-3 1-6 6-2 to the American.
She became the 15th women's seed to be knocked out as the second round got under way in Paris on Wednesday.
Stearns, 21, is playing in her first overseas Grand Slam after making her major debut at last year's US Open.
Her first-round victory over doubles world number one Katerina Siniakova was her first at a Grand Slam.
She will face Russian ninth seed Daria Kasatkina or Marketa Vondrousova of the Czech Republic in the third round.
Third seed Jessica Pegula advanced as Italy's Camila Giorgi withdrew through injury after losing the first set 6-2.
American Pegula will next play Belgian 28th seed Elise Mertens, who defeated Colombia's Camila Osorio 6-3 7-6 (7-3).
Earlier, Ukraine's Elina Svitolina recovered from a shaky start to beat Australian Storm Hunter 2-6 6-3 6-1.
Three-time French Open quarter-finalist Svitolina, making her Grand Slam return after becoming a mother in October, will play French fifth seed Caroline Garcia or Russian Anna Blinkova in the third round.
