Sloane Stephens had lost in the first round in Monterrey and Melbourne earlier this year but won in Miami on Wednesday.
Zarina Diyas got the better of "legend" Venus Williams at the Miami Open, while there were wins for Shelby Rogers and Ajla Tomljanovic.
Leylah Fernandez, 18 broke through for her first trophy with a 6-1 6-4 victory over qualifier Viktorija Golubic on Sunday.
Daria Kasatkina became the first player to win two WTA tournaments in 2021 after lifting the St Petersburg Ladies Trophy.
Leylah Fernandez and Viktorija Golubic upstaged seeds to move through to Sunday's final in Monterrey.
Daria Kasatkina and Margarita Gasparyan will contest the St Petersburg Ladies Trophy final on Sunday after denying a pair of Russian greats.
Zheng Saisai was the latest top seed to bow out at the Monterrey Open with Ann Li reaching the semi-finals.
Ekaterina Alexandrova was eliminated from the St Petersburg Ladies Trophy by a wildcard, while Daria Kasatkina and Vera Zvonareva both won.
Zheng Saisai eased into the Monterrey Open last eight where she will face fellow seed Ann Li.
Romanian qualifier Jaqueline Cristian is the only non-Russian player in the last eight of the St Petersburg Ladies Trophy.