World number 83 Flavia Pennetta has expressed her happiness with the Italian domination at the US Open.

The 31-year-old overcame Simona Halep 6-2 7-6 in the fourth round to set up a last-eight meeting with compatriot Roberta Vinci.

Vinci advanced past fellow Italian Camila Giorgi to reach the quarter-finals, and Pennetta insists that there is a lot of support exchanged between her and her countrywomen.

"We try to motivate everyone," Pennetta told reporters. "It's really nice because always we make a good result, almost always."

Giorgi caused a shock upset in the third round by eliminating world number eight Caroline Wozniacki.