I did a frame-by-frame analysis for i News in the UK. There was, of course, no black magic involved! Check out the images below (click on image for a larger view).
As Ronaldo planted his left boot, a pressure wave was initiated in the turf. A crinkle was all it took to get the ball to hop off the turf about a centimeter. Click here for more details in the story by Will Magee. Getting ball off the turf prior to kicking saved a little energy loss from friction between the ball and turf. Hard to stop that shot!