Adobe Illustrator: put a radial gradient over solid background

I am trying to create 3d ball in Illustrator. I have the following strategy:

• create a solid colour background;
• create a “diffuse” shape;
• create a “reflection” shape;
• mix them together.

Final result should look like this:

The problem is that radial gradient has a “background” color. To mix it with background figure properly I use “multiply mode”, but then it mixes active colour as well.

Another solution might be to create a radiant gradient from transparency to active colour, but how?

How do I create such a illustration, consisting of two shapes in AI:

Answer

Attribution
Source : Link , Question Author : Denis Kulagin , Answer Author : Community