Cropping a QRegion for setMask

I am setMask()'ing a QRegion I've a Big QRect of that I am making a Circle

//config->rectangle = QRect(0,0 275x275)
QRegion circleRegion(config->rectangle, QRegion::Ellipse)

and now I've a small widgetRect QRect(43,0 93x110) that area I need to crop from the previous region and use for setMasking.

What I am doing circleRegion.intersected(widgetRect) which is not giving me the proper result. I am expecting a Pie Reg开发者_JAVA百科ion. Where am I missing ?