Vote: Which was your favorite rally of the Charleston quarterfinals?

The Credit One Charleston Open is down to the last four. But which was your favorite rally from quarterfinal day?

Daria Kasatkina

View Profile  demonstrated the art of the lob throughout her defeat of Jaqueline Cristian, frequently leaving the Romanian only able to turn and watch another pinpoint shot drop just inside the baseline. This elegant drop shot-lob combination might have been the best.

After nearly three hours, Kasatkina also brought up her first match point in style, tracking down a Cristian drop shot to conjure an even sharper counter-angle in response on the 20th shot of the point.

Jessica Pegula

View Profile  also pulled off a remarkable counter-drop deep into the third set of her tussle with Victoria Azarenka

View Profile , having had to scamper to every corner of the court in the preceding rally.

The real drama was still to come in Pegula's wild win, though. The No.1 seed missed her first four match points, but then saved four in the deciding tiebreak, three with clean winners. The last of those was the best, with the tension ratcheting up in every stroke as Pegula forced herself to stay on the front foot before finding the winning backhand angle.

Maria Sakkari

View Profile  gave a textbook lesson in how to redirect the ball against Veronika Kudermetova

View Profile , responding to a sharp backhand angle from her opponent by simply hammering it down the line, squarely into the corner.