Last year's finalist Stephens safely through after stopping Doi in second-set tiebreak.
Gallery: Seeded stars step out
Angelique Kerber, seeded fifth, fell to Anastasia Potapova - her third first-round loss in Paris in the past four years.
- © Julien Crosnier / FFTSolid start for Sloane
- © Corinne Dubreuil / FFTPress conference: Roger Federer
Roger Federer speaks to the media following his first-round win on Sunday.
- © Cedric Lecocq / FFTRoland-Garros jargon explained
From terre battue to La Monf, les serres to simple dames, your dictionary is here.