Paris - American qualifier Bethanie Mattek-Sands finished off Kristina Barrois of Germany with her 10th ace to secure a 7-6 (7/3), 6-2 win and reach the second round of the Open GDF Suez on Wednesday.
Barrois rallied from a 4-1 deficit to force a tiebreaker. But Mattek-Sands won six straight points to take the first set then broke Barrois twice in the second.
Mattek-Sands will next play seventh-seeded Roberta Vinci, who beat Simona Halep of Romania 6-4, 6-4.
Klara Zakopalova of the Czech Republic and Monica Niculescu of Romania also advanced, along with French wild card Pauline Parmentier and American teenager Christina McHale.
Parmentier jumped out to 3-0 in the final set and hit a backhand cross-court winner to edge eighth-seeded Anabel Medina Garrigues of Spain 2-6, 6-3, 6-3.
The Frenchwoman had 31 winners to only 15 for Medina Garrigues.
McHale beat lucky loser Varvara Lepchenko 6-4, 7-5 in an all-American match.
Niculescu outlasted Jarmila Gajdosova of Australia 6-1, 4-6, 6-4 in an erratic match of 14 service breaks.
Zakopalova cruised past French wild card Alize Cornet 6-3, 6-1 by winning eight straight games to 5-0 in the second.