April 2017 WTA Breakthrough of the Month Finalists:
Daria Kasatkina: Kasatkina's breakthrough came at the Volvo Car Open; a year after reaching the quarterfinals on her debut appearance, the Russian teenager rolled to her maiden WTA title in Charleston, knocking out Laura Siegemund and fellow teen Jelena Ostapenko in the final.
Marketa Vondrousova: The Czech teen rang in the inaugural Ladies Open Biel Bienne by becoming the lowest-ranked woman to win a WTA title since 2009, when an unranked Kim Clijsters won the US Open. Vondrousova used her big lefty power to upset top seed Barbora Strycova and Anett Kontaveit en route to the trophy.
Anett Kontaveit: Speaking of Kontaveit, the Estonian youngster took her first-ever WTA final appearance in Biel/Bienne and applied it to another impressive week at the Porsche Tennis Grand Prix, stunning reigning Roland Garros champion Garbiñe Muguruza to reach the quarterfinals in Stuttgart as a qualifier.
Dayana Yastremska: In a year that has seen 2016's junior talents break through en masse on the WTA level, Yastremska is the latest in a talented cohort that includes Anastasia Potapova and Amanda Anisimova. The 16-year-old won her first two WTA main draw matches to reach the quarterfinals at the TEB BNP Paribas Istanbul Cup.