Karolina Muchova marked her return after reaching the Wimbledon quarter-finals by powering into the second round of the Bronx Open.
The Czech, who proved one of the biggest surprises at the All England Club, had too much for Slovakia's Viktoria Kuzmova as she advanced 7-5 6-2.
In the second round, Muchova will come up against American wild card Kristie Ahn, who overcame Jil Teichmann of Switzerland 6-3 6-4.
Fifth seed Katerina Siniakova beat Yafan Wang of China 6-3 6-2, while ninth seed Aliaksandra Sasnovich also advanced with a 6-3 6-2 win over Polona Hercog.
But fourth seed Shuai Zhang fell to Germany's Andrea Petkovic, who recovered her confidence with a 6-3 6-4 win in one hour and 23 minutes.
