Samantha Stosur has continued her encouraging buildup to the US Open by beating Belgian Kirsten Flipkens to advance to the semi-finals of the Connecticut Open.

Stosur won a tight quarter-final 6-3 4-6 6-3 against Flipkens on Thursday to set up a clash in the last four with No.2 seed Petra Kvitova.

Kvitova won an all-Czech encounter against Barbora Zahlavova Strycova 6-4 6-1.

In other quarter-final action in the hardcourt event, Italy’s Camila Giorgi beat Spain’s Garbine Muguruza 6-4 6-7 (4-7) 6-2 and Slovakian Magdalena Rybarikova overcame a horror second set to down American Alison Riske 7-5 0-6 6-4.

Stosur has been seeded 24th for the US Open beginning at Flushing Meadows on Monday.

The 2011 Open champion will take on American Lauren Davis in round one of the final grand slam tournament of the year.