Mary Pierce avenged her loss in the final of this year's French Open at the hands of Justine Henin-Hardenne by dispatching the Belgian at the US Open.
The Frenchwoman looked sharper and more determined than the former champion as she notched up a 6-3 6-4 victory.
Henin-Hardenne made a sluggish start and Pierce took advantage racing to the first five games on her way to the set.
The players exchanged breaks in the second but Pierce had the edge and booked her place in the quarter-finals.
Pierce got off to a lightning start on Arthur Ashe Court with some attacking play at the net.
The 12th seed quickly went 5-0 ahead but Henin-Hardenne roused herself to break back at 5-2.
But despite forcing another break-point, the Belgian could not get the set back on level terms as Pierce stayed strong.
At the start of the second set Henin-Hardenne appeared to be struggling with her hamstring and Pierce pounced on her weakness to gain a quick break.
Again, the French Open champion dug deep with some strong returns to break back.
But Pierce's superior groundstrokes and movement saw her break again in the fifth and she sealed victory with her fourth match-point.
The 30-year-old now meets compatriot Amelie Mauresmo in her third quarter-final at Flushing Meadows.
"I was playing unbelievable in the beginning," said Pierce, who recorded her first victory over Henin-Hardenne in five attempts.
"But I think she started playing better and it became tough.
"I just gave everything I had tonight, fought and didn't give up."