British number one Elena Baltacha has been knocked out of the Citi Open with defeat by Virginie Razzano in the second round.
The world number 57, seeded six in Maryland, won only one point on her second serve in the second set as she lost 6-4 6-2.
Fellow Briton Heather Watson plays Canada's Stephanie Dubios on Thursday.
Elsewhere, second seed Nadia Petrova reached the third round with a 6-2 6-2 victory over Canada's Eugenie Bouchard.
Fifth seed Bojana Jovanovski defeated Jill Craybas 6-4 5-7 6-4, but China's Zhang Shuai was forced to retire because of a heat-related illness in the day's other match after losing the first set 6-4, sending Irina Falconi of the United States through.
For Razzano, the victory over Baltacha is her first back-to-back win since her fiance and coach Stephane Vidal died in May.
"For me it is [a tribute] already done, because I won two matches in a row," she said.
"He is happy because I made a good start, played two very good matches. The more I win matches there is more confidence for me.
"I'm going positively. Go to win. I win for him and for me. First for him, then for me.
"I played a great match. I'm feeling good with my tennis. I was very serious, focused on my game. I was able to concentrate on my goals from the start."